
Class 

Book 0<fS 
Copyright N° 

COPYRIGHT DEPOSIT. 



LESSONS IN PHARMACY 



BY 

OSCAR OLDBERG, Pharm.D., 

DEAN OF NORTHWESTERN UNIVERSITY SCHOOL OF PHARMACY 



A COURSE OF STUDY FOR HOME STUDENTS 



CHICAGO 
INTERSTATE SCHOOL OF CORRESPONDENCE 



AFFILIATED WITH NORTHWESTERN UNIVERSITY, EVANSTON— CHICAGO 






LIBRARY of CONGRESS 
Two CoDies Received 

MAY 21 1906 

opyrigM Entry 

flo 



CLASS ' (A, XXc. No, 
COPY B. 



Copyright, 1904, by Bellows Brothers Company 



Copyright, 1905, by Bellows Brothers Company 



Copyright, 1906, by Bellows Brothers Company 







PUBLISHER'S NOTE 

A CORRESPONDENCE COURSE IN PHARMACY Was Written 

expressly for the home student who wishes to prepare for the 
examinations given by state boards of pharmacy or for 
more extended courses in technical schools, such as the 
School of Pharmacy of Northwestern University. 

Dr. Oscar Oldberg, the author of the course, was born in 
Sweden in 1846 and educated in the Gymnasium at Gene. 
He became a licensed practitioner in pharmacy, and since 
coming to the United States has risen rapidly into promi- 
nence. Since the establishment of its School of Pharmacy 
by Northwestern University in 1886, he has been professor 
of pharmacy in that institution and dean of its faculty. 
During this time he has been an editor of pharmaceutical 
journals and is the author of a number of text-books on 
pharmacy, chemistry, metrology and related subjects. In 
1880 he became a member of the committee of revision of 
the United States Pharmacopoeia, and has been in active 
connection with the committee ever since. 

Not only have Doctor Oldberg's training and experience 
fibted him to write a course of study which could be followed 
by students at home, but he has himself had wide experience 
in directing students under similar conditions. Accord- 
ingly, this course may be relied upon to be as simple as con- 
ditions warrant, and so practical that no well prepared stu- 
dent need fear his ability to carry it through. 

The papers of the student will be corrected by teachers 
experienced in correspondence work who have been selected 



publisher's note 

by the School under the approval of Doctor Oldberg. The 
papers written by the students, bearing the careful criticisms 
and suggestions of the teachers, will be returned in all cases 
to the former, accompanied by extended and accurate 
printed answers, which will enable the student to compare 
his own work with the perfect standard. 

Interstate School of Correspondence. 

Chicago, April, 1906. 



A CORRESPONDENCE COURSE IN 
PHARMACY. 

LESSON ONE 

To the Student: 

Read this introductory letter carefully before you begin your 
study. 

This course is the result of long years of classroom experience, in 
which the author and his students were in daily conversation. To 
adapt this instruction to the needs of the home student has been a 
pleasing task that, it is hoped, has been successfully accomplished. 

Though a large number of different subjects are treated in the 
course, it is a unit. All the parts are closely related and are integral 
portions of pharmacy. The course is divided into chapters, and 
the chapters into paragraphs numbered consecutively from the first 
lesson to the last. The entire work is thus easily available for cross 
reference. The chapters are grouped into lessons of approximately 
equal length and difficulty. The early lessons are simple and con- 
sist largely of definitions and general principles. Later lessons may 
be more difficult, but it is thought that the logical arrangement and 
the gradual development of your knowledge will enable you to handle 
the more technical subjects with ease. 

Only the first two lessons are sent you at this time. When you 
have mastered the first lesson, write your recitation paper and mail 
it to us in the manner and form described in the Student's Guide 
which was sent you with this lesson. Then, without waiting for 
returns from us, proceed at once upon the study of your second lesson. 
More explicit directions are given in the Students Guide. If this 
plan is followed intelligently you will always have work on hand and 
will not be delayed by the passage of your papers through the mails. 

Your papers will be read with care by an expert instructor. His 
suggestions, directions and criticisms will be plainly marked in red 

1 



2 A CORRESPONDENCE COURSE IN PHARMACY 

ink on your recitation paper and returned to you for further consid- 
eration. 

When the course has been completed in a satisfactory manner, 
your diploma will be sent to you and at the same time you will be 
given the entire course handsomely bound. This you will always 
find a valuable reference work. 

If, in the preparation of all your lessons, you work as directed, you 
will find when you complete your course that you are thoroughly 
versed in the subjects taught. We wish you to obtain the greatest 
possible benefit and are sure that you can, do so only by observing 
the following general directions: 

1. Be regular, systematic and persistent in your work. Select some 
stated time for your daily study and let nothing interfere with it. 

2. If possible, devote at least a full hour to study each day. While 
you can accomplish something in less time, yet you will find that 
your thought will be much clearer if you can work continuously for 
at least that period. 

3. The best plan is to begin by reading the first chapter through 
to the end. This gives you a general idea of what you are expected 
to learn. Then proceed to more careful study. Do not memorize 
the definitions, but get the thought so thoroughly that you can make 
a definition for yourself. 

4. You will meet many new words and not a few that are difficult. 
Use whatever reference books are at hand. The International Dic- 
tionary contains most of the words used in the course, but some of 
them are so technical that they are not to be found there. However, 
the number of words not to be found in the Dictionary is so small 
that you can afford to look for everything of whose meaning and 
pronunciation you are not certain. Encyclopedia articles on all the 
subjects mentioned are helpful, especially those of the more recent 
publications. It is always worth your while to. watch for articles on 
topics kindred to your lesson in newspapers and magazines. The 
habit of looking for such things will always be valuable to you. 

5. Study broadly. Try to see all sides of every subject. Have 
ideas of your own and do not follow slavishly the words of your text. 

6. Put yourself into your work. Spend the last part of every study 
hour in carefully thinking over what you have done. Close your 
book and try to recall all that you have read. If you persist in this 
exercise you will be surprised at the increase in your power to hold 
what you have read. 

7. Take time to do your work well. Be patient and thorough, 



INTKODUCTORY 3 

and then be satisfied with small progress at first. As you get further 
into the subject you will learn more rapidly. 

8. These general directions are worth following throughout the 
course, and from time to time, as you need it, specific advice will be 
given. 

9. Do not hesitate to write us on any subject connected with the 
course which puzzles you. Your letters will always be answered 
promptly and with pleasure by us. Address, always, 

Interstate School of Correspondence, 

378-388 Wabash Avenue, Chicago, 111. 



Introductory 

1. Medicines are substances employed to relieve, counter- 
act, remove or prevent disease or pain, or to defend or 
promote health. 

2. Poisons are substances which, when taken into the 
body in small quantities, are liable to do serious or fatal 
injury. 

The meaning of the term poison cannot be sharply defined, 
because some substances may be beneficial or wholesome 
under certain conditions, or when used in relatively small 
amounts, but s decidedly hurtful or even fatal to life under 
other conditions or in greater quantities. 

3. Since it is evident that disease and pain are associated 
with abnormal states of the parts of the body and their 
functions, substances that greatly affect those parts and 
functions are employed as medicines. 

The most valuable medicines accordingly include 
substances which are poisons when abused or ignorantly 
used, and it is mainly for this reason that all civilized 
nations prohibit the practice of medicine by persons not 
possessing a thorough knowledge of the human body and the 
disorders to which it is subject, and of the nature and effects 
of medicines. For the same reason, also, the laws of all 



4 A CORRESPONDENCE COURSE IN PHARMACY 

civilized countries forbid the practice of pharmacy by 
persons not specially trained for the safe performance of its 
duties. 

4. Pharmacy (from Greek p7iarmahon, medicine) is the 
scientific-technical business of selecting, preparing and 
dispensing medicines. 

The selection of medicinal substances requires the ability 
to identify them and to determine their quality, purity and 
strength. Properly to prepare and dispense medicines 
requires an intimate knowledge of their composition and 
properties and of the laws of chemistry and pharmacy, 
together with ample practical experience and skill. 

5. Materia Pharmaceutica. The materials out of which 
medicines are made are derived from the mineral, the 
vegetable and the animal kingdom. They include not only 
substances of decided medicinal activity, but many materials 
which are valuable chiefly because they are quite without 
any medicinal effect of their own. 

Hydrocyanic acid, strychnine, morphine and numerous 
other deadly poisons are medicines of great value; but 
water, sugar, lard, wax, starch, gelatin, and other things 
used as diluents or solvents, or to give body and form to the 
preparations into whose composition they enter, are also 
important pharmaceutical materials. 

6. Crude Drugs are medicines, and other pharmaceutical 
materials consisting of unchanged or but little altered or 
prepared natural products, such as minerals, roots and 
other plant organs, gums, resins, etc. But the "crude 
drugs" also include many products manufactured on a large 
scale for various industrial purposes, such as lime, the 
commercial or raw chemicals, catechu, tar, alcohol, etc. 

7. The Inorganic or Mineral Drugs are comparatively few. 
Among them are chalk, marble, lime, alum, copperas, 
blue vitriol, litharge, sugar of lead, sulphur, black sulphide 



INTRODUCTORY 5 

of antimony, black oxide of manganese, mercury, zinc, iron, 
bismuth, borax, saltpeter, the commercial impure acids and 
alkalies. 

When these crude inorganic substances have been purified 
or converted into preparations suitable for immediate 
medicinal use, they are no longer called drugs, but chemicals 
and pharmaceutical preparations. 

8. The Vegetable Drugs are numerous and the most 
important of all crude drugs. They include not only whole 
plants and parts or organs of plants, as herbs, leaves, 
flowering tops, twigs, roots, underground stems, barks, 
fruits and seeds, but also plant exudations such as gums, 
resins, gum-resins, oleoresins, and such manufactured prod- 
ucts as opium, catechu, kino, aloes, starch, sugar, olive oil, 
castor oil, linseed oil, oil of turpentine, cottonseed oil, and 
many other commercial commodities. 

About two or three hundred plant drugs are important 
enough to be described in pharmacopoeias. 

9. Animal Drugs were formerly more common than now. 
Those at present employed include cantharis (Spanish fly), 
musk, castor, ox-gall, cod-liver oil, lard, suet, wax and 
honey. 

Pepsin, pancreatin, dried animal glands, and extracts 
prepared from animal organs, glands and tissues, are manu- 
factured products which may be more properly called 
pharmaceutical preparations, although the pharmacist who 
dispenses these medicines is rarely the preparer of them. 

Not a score of animal drugs are medicinally important. 

10. Medicinal Chemicals are unmixed single substances of 
definite chemical structure, such as single elements and 
chemical compounds in a pure state. Familiar examples 
are sulphur, iodine, calomel, quinine, carbolic acid, chloro- 
form, potassium bromide, chloride of iron, glycerin, cream 
of tartar, Epsom salt, nitrate of silver. 



6 A CORRESPONDENCE COURSE IN PHARMACY 

Simple water-solutions of chemical compounds are fre- 
quently called chemicals. 

11. Inorganic Chemicals are those prepared from materials 
derived from the mineral kingdom. They are for the most 
part compounds of potassium, sodium, lithium, calcium, 
magnesium, aluminum, iron, silver, gold, copper, lead, zinc, 
bismuth and other metals, and the compounds formed by 
the non-metallic elements, chlorine, bromine, iodine, 
sulphur, phosphorus, arsenic and antimony with one another, 
and with oxygen and hydrogen. 

About three hundred inorganic chemicals are sufficiently 
important to be mentioned in the pharmacopoeias. 

12. Organic Chemicals are those prepared from materi- 
als derived from plants or animals, or from coal oil and 
coal tar, and from artificially produced hydrocarbons 
(compounds of carbon and hydrogen) and their deriva- 
tives. The organic chemicals are composed chiefly of the 
elements carbon, hydrogen and oxygen, and frequently 
nitrogen. 

About sixty or seventy organic chemical substances are 
mentioned in the pharmacopoeias. 

13. But many chemicals are of such composition that 
they belong to both inorganic and organic chemistry. Such 
are, for instance, the salts formed by organic acids with the 
inorganic bases, and by the inorganic acids with organic 
bases. 

Tartaric acid is obtained from grapes and citric acid 
from lemons; they are, therefore, organic acids. These 
organic acids form salts (called tartrates and citrates) with 
several of the metals, as potassium, sodium, magnesium, 
iron, etc. 

Sulphuric, nitric and phosphoric acids are inorganic 
acids; but they form salts with quinine, morphine, 
strychnine and other organic bases derived from plants. 



INTRODUCTORY 7 

14. Pharmaceutical or Medicinal Preparations are sub- 
stances prepared either by manufacturing pharmacists or 
by dispensing pharmacists expressly for medicinal uses. 

Distinction must be made between stock preparations 
which are rarely finished medicines, &11& finished medicines 
which are rarely kept in stock. 

Stock preparations are generally made by such time- 
consuming methods that they cannot be prepared for the 
occasion whenever they are wanted but must be made in 
advance of the demand for them. But the stock prepara- 
tions may or may not be medicines ready for immediate 
administration or application. Many of them are simply 
materials which require further treatment by the dispensing 
pharmacist in order to convert them into convenient and 
effective forms for medicinal uses, or they are combined or 
mixed with other substances to subserve the requirements 
of individual cases. Other stock preparations are finished 
medicines prescribed by physicians and dispensed by 
pharmacists without modification. 

4 Stock preparations may be prepared either by manu- 
facturers or by dispensing pharmacists; bjjt they are chiefly 
made by manufacturers. 

By way of illustration, we may say that manufacturing 
pharmacists make such preparations as extracts and fluid 
extracts of vegetable drugs. They supply these and other 
stock preparations to the dispensing pharmacists, who use 
them as materials for preparing finished medicines ordered 
by physicians. Extracts, fluid extracts, oleoresins, tinc- 
tures and many other classes of pharmaceutical preparations 
are rarely used without modification, dilution, or other 
treatment, or without combination with other materials. 

A dispensing pharmacist may make the stock preparations 
he uses, and a manufacturer may manufacture pills and other 
preparations which are finished medicines ready for imme- 



8 A CORRESPONDENCE COURSE IN PHARMACY 

diate use. But only the dispensing pharmacist expressly 
licensed to practice pharmacy is permitted to compound and 
dispense medicines upon physicians' prescriptions. 

15. Galenical Preparations are pharmaceutical preparations 
prepared by methods which do not result in chemical 
alterations of the ingredients employed. The transforma- 
tions of one or more substances into* one or more other 
substances are chemical alterations; but mere mechanical 
mixtures, solutions and extracts contain no new sub- 
stances formed out of the original substances employed as 
materials. 

The pharmaceutical solutions are water solutions, alcoholic 
solutions, and solutions made with mixtures of alcohol and 
water, or with other solvents. 

The extracts are either liquid or solid, and the solvent 
or menstruum employed to make an extract may be water, 
alcohol, wine, diluted acetic acid, or some other liquid. 
The extracts include infusions, decoctions, tinctures, wines, 
vinegars, fluid extracts, solid extracts and oleoresins. 

The mixtures include not only those made out of liquids, 
but also mixtures of solids and liquids together, and out of 
solid substances only. Numerous liquid mixtures are used, 
and of the dry or solid mixtures we may mention compound 
powders, pills, troches, ointments, etc. 

But there are also Galenical preparations not readily 
classified because they are partly solutions, partly mixtures 
and partly extracts, or belong to more than one class. 

Galenical preparations are so named after Galen, because 
the preparations made and used by that physician and 
teacher did not include any chemicals or any substances 
prepared by intelligent chemical processes, since chemistry 
was unknown in his time. 

About three hundred Galenical preparations are important 
pharmacopceical medicines. 



INTKODUCTOKY 9 

16. Chemical Pharmaceutical Preparations are those pro- 
duced by chemical means. Whenever the materials employed 
in making the preparations are transformed into new 
substances, the product is a chemical preparation, and the 
process of preparing it is a chemical process. The principal 
materials employed in making the preparation called 
solution of acetate of ammonium are acetic acid and 
ammonium carbonate. But the product contains no 
ammonium carbonate whatever and very little acetic acid; 
it contains instead a compound called ammonium acetate, 
which was produced out of the acetic acid and ammonium 
carbonate. Solution of acetate of ammonium is, therefore, 
a chemical preparation. 

All salts, acids, and other chemicals are chemical prepa- 
rations; but there are many chemical pharmaceutical 
preparations which are of indefinite composition, or which 
are mixtures of several substances, and hence are not true 
chemical compounds, as, for instance, tincture of chloride 
of iron, syrup of ferrous iodide, "effervescent salts," etc. 

17. Extemporaneous Preparations are those not kept in 
stock but prepared for the occasion whenever required. 
They include such products as would deteriorate or decom- 
pose in a comparatively short time, as well as medicines 
specially ordered to be prepared in accordance with magistral 
formulas or prescriptions written by physicians to meet the 
requirements of individual cases. 

A magistral formula (from magister, master) is a formula 
or recipe written by one who is authorized or competent to 
compose prescriptions. 

18. Pharmacology is that branch of the study of medicine 
which treats of the materia medica, or medicinal substances, 
and of their sources, commercial history, preparations, 
effects, uses and doses. 

More recently the term pharmacology has been employed 



10 A CORRESPONDENCE COURSE IN PHARMACY 

in a more restricted sense or to signify the study of 
pharmaco-dynamics. 

19. Pharmacography is that branch of the study of 
medicine which treats of the natural origin, appearance, 
structure and other means of identification of organic 
drugs. 

Pharmacognosy is the knowledge of pharmacography. 

The study of pharmacography necessarily demands a 
good knowledge of the organs, tissues and microscopical 
structure of plants. 

20. Pharmaco-dynamics is the action of drugs or 
medicines, or the study of the quality, quantity and direction 
of their effects. 

21. Pharmacopoeias are books compiled by recognized 
national authorities establishing the titles, definitions, 
descriptions, tests, formulas, and standards of quality, 
purity and strength of the medicinal substances employed 
by licensed physicians and surgeons. 

Every civilized country has a national pharmacopoeia of 
its own, or uses but one pharmacopoeia, even if that be the 
pharmacopoeia produced by some other country. 

22. The Official medicinal preparations, processes, titles, 
definitions and descriptions of any country are those 
contained in the pharmacopoeia of that country. 

23. An Officine is the workshop or place of business of a 
dispensing pharmacist. In America the drugstore con- 
stitutes or contains the officine; but the precise location of 
the drugstore is not specifically fixed by law. In nearly all 
the countries of Europe the locale of the apothecary's 
shop or officine is fixed by the government and cannot be 
changed except by its express permission. The permission 
to remove an apothecary's shop from one location to 
another is given in those countries only in cases where the 
change is found to be warranted and not contrary to the wel- 



PHAKMACEUTICAL EDUCATION 11 

fare of the community served by that officine, and in each 
case the authorized new location is specifically placed on 
record. In those countries, therefore, not only the pharma- 
cist or druggist is registered and licensed, but every offi- 
cine or pharmacy or drugstore or apothecary's shop is also 
registered and licensed, and that independently of the tem- 
porary owner or manager. 

24. Officinal Drugs, chemicals and preparations are those 
commonly found in an officine or pharmacy. 

An officinal medicine is often unofficial, and an official 
medicine is not necessarily officinal. 

25. A Pharmacist is a specially trained scientific-technical 
expert competent safely to prepare and dispense medicines. 



II 

Pharmaceutical Education and the Legal Regulation 
of the Practice of Pharmacy 

26. Pharmacy Laws exist in all civilized countries. They 
are public health laws, enacted for the sole purpose of 
protecting the people against the grave dangers to health 
and life which necessarily attend upon ignorance, incom- 
petence, negligence and irresponsibility in the business of 
supplying medicines for the sick, and upon unrestrained 
traffic in poisons. 

The physician would be powerless without medicines. 
The welfare of the community, therefore, demands that 
necessary medicines shall be promptly procurable. Hence 
it is made the duty of designated public servants to be at 
all times ready to prepare and dispense commonly employed 
and specially important remedies without unnecessary 
delay. These public servants are the pharmacists. They 
are necessarily given the exclusive right to practice 



12 A CORRESPONDENCE COURSE IN PHARMACY 

pharmacy, and that right is expressly forbidden to all others. 
Thus the exclusive privilege of the pharmacist to practice 
his profession imposes upon him the obligation to perform 
faithfully his functions. He must not only qualify himself 
to perform his duties intelligently and safely, but must 
fulfill his obligations by actually rendering the services 
assigned to him. In most countries he is, therefore, 
required to make oath, before his license to practice becomes 
effective, that he will faithfully perform his duties to the 
community, uninfluenced by fear or favor, loss or gain, and 
his work is at all times subject to that supervision which 
must be exercised by the government to insure to the people 
the benefits for which the pharmacy laws and regulations 
exist. As not only the pharmacists and their assistants but 
the pharmacies or drugstores, too, are registered, the 
pharmacies are inspected annually or oftener by a special 
inspector, just as banks are inspected. . 

England and America are the only countries in which 
this is not done. 

27. All well-made pharmacy laws take cognizance of 
three distinct classes of persons necessarily engaged in the 
performance of the pharmaceutical work of the drugstores, 
or pharmacies : Managers, clerks and apprentices. 

The respective qualifications, duties, privileges and 
responsibilities of each of these three classes of pharma- 
ceutical workers are sharply defined and prescribed in all 
countries where the practice of pharmacy has reached its 
highest present development and where it has been 
regulated by law for centuries. In America, however, 
many of the State pharmacy laws make no distinction 
between them, and in only two States (New York and 
Illinois) does the law contain the specific requirement that 
all apprentices must satisfy the Board of Pharmacy that 
they possess sufficient preliminary general education to be 



PHARMACEUTICAL EDUCATION 13 

fit to learn pharmacy and to undertake the study of 
chemistry and the other subjects which are necessary to 
intelligent pharmacy, and upon which all candidates for 
registration as pharmacists or assistant pharmacists are 
therefore examined. Yet, of all the requirements of sound 
pharmaceutical legislation, the most important is good 
general education. All pharmacy laws, in America as well 
as everywhere else, do, of course, demand of all persons 
who desire to be registered as pharmacists or assistant 
pharmacists, that they must be competent to perform their 
duties intelligently and safely and they cannot be competent 
if their education is deficient, but a definite standard of 
preliminary general education is a fundamental necessity, 
and therefore of far greater importance than any other 
feature of the law. 

28. Managers of pharmacies, whether they are the 
owners or not, are responsible for their own acts as such 
and also for the acts of any persons in their employ who 
are not legally qualified to perform the duties assigned 
them. Managers are also responsible for the character of 
the medicines, or materials employed in the preparation of 
medicines, dispensed by themselves and others in the 
pharmacies under their charge. They must accordingly 
possess the technical training necessary to enable them intel- 
ligently to examine, identify, test or prepare the medicinal 
substances requiring it. 

29. Clerks in pharmacies who do any pharmaceutical 
work, whether they be Eegistered Pharmacists or Eegistered 
Assistant Pharmacists, are not responsible for the identity, 
quality, purity, strength or condition of the medicines they 
dispense, or the materials they are required to use in 
preparing and dispensing medicines, except so far as they 
may dispense medicinal substances which they themselves 
know to be spurious or to deviate from recognized standards 



14 A CORRESPONDENCE COURSE IN PHARMACY 

of purity, quality or strength. But they, and not their 
employers, are responsible for the correctness of their own 
work, if they are registered or licensed. 

30. Apprentices are not permitted to do any technical 
pharmaceutical work nor to dispense any medicine except 
under the direct supervision of the Registered Pharmacists 
and Registered Assistant Pharmacists by whom they are 
employed or who are their preceptors. They are necessarily 
permitted to assist in the daily technical work in order 
that they may learn the art and, in time, become qualified 
to succeed their preceptors or practice pharmacy on their 
own responsibility. They are responsible for any unlawful 
act performed by them, and for any act of theirs not 
authorized by their employers or preceptors. But they 
are not accountable for any act performed by them under 
the direction of their employers or preceptors unless such 
act is one prohibited by law. 

31. Three kinds of training are each and all absolutely 
necessary to fit any person for the intelligent and safe 
practice of pharmacy. They are: 1, Good general education; 
2, good special education in botany, chemistry, pharmacog- 
nosy and pharmacy; and 3, good shop training in the 
actual performance of pharmaceutical work in the pharmacy. 

32. t The occupation of the pharmacist is truly a scientific- 
technical profession worthy of the highest ambition. The 
best education obtainable in our universities and colleges 
cannot be regarded as too high for the practice of scientific 
pharmacy, for it but serves to arm the pharmacist for 
greater usefulness and achievements. Practicing pharmacists 
with doctor's degrees in philosophy or medicine are not rare 
in Europe. In past times a large proportion of the most 
renowned chemists of the world were pharmacists. The 
practice of pharmacy offers limitless opportunities for 
scientific research to all who are competent to do such work. 



PHARMACEUTICAL EDUCATION" 15 

The drug business as ordinarily conducted in England 
and America is not pharmacy. But pharmacy is still 
practiced in many of the best drugstores, and it will survive 
and be in time entirely divorced from the mercantile 
business which has so debauched it and nearly crushed it 
out. 

Legitimate pharmacy will prevail because it is necessary 
to civilization. 

The ordinary drug business requires large capital. Large 
rent, expensive furniture, a varied and heavy stock of 
merchandise, the wages of the salesmen, and the small 
profits due to excessive competition, not only with other 
drugstores but with groceries, dry-goods stores, candy shops, 
ice-cream parlors, cigar stores, stationery stores, paint 
stores, department stores and many other retail shops, 
render it necessary that the volume of trade shall be very 
great before the merchant-druggist can hope to make his 
business pay. But if he is a shrewd, careful and industrious 
merchant he succeeds as a merchant whether he be a 
pharmacist or not. His drug department is largely made up 
of quack nostrums and proprietary products. The prescrip- 
tion department is frequently an insignificant fraction of his 
establishment and sometimes wholly absent. Legitimate 
professional pharmacy cannot be expected to flourish amid 
such surroundings. 

Scientific-technical pharmacy is something altogether 
different. Thirty years ago pure scientific pharmacy, free 
from extraneous merchandising, was almost unknown in 
America. Yet the drugstore of thirty years ago did far 
more real pharmaceutical work and less miscellaneous 
merchandising than the average drugstore of to-day. But 
hundreds of pharmacists are at last discovering that true 
professional pharmacy completely divorced from mere 
trading is both practicable and profitable in every sense. 



16 A CORRESPONDENCE COUESE IN PHARMACY 

They find that they can succeed better without dealing in 
quack nostrums, cigars, soda water, ice cream, perfumery, 
stationery, rubber goods, toilet . articles, books, paints, oils, 
glass, chewing gum, and other articles foreign to pharmacy. 
They devote themselves wholly to the preparation and 
dispensing of medicines on physicians' prescriptions, and 
to such other technical work as they may be called upon to 
do, such as urine analysis, etc. To do this business suc- 
cessfully requires perhaps less than one-fifth the capital 
necessary to make the ordinary drug business pay. The 
current expenses of purely pharmaceutical practice are 
small, because a couple of rooms upstairs at a small rent 
will be found sufficient. The monthly bills for "goods" are 
insignificant, because nearly all the goods bought are the 
materials necessary to dispense prescriptions. The scien- 
tifically trained technical experts who practice professional 
pharmacy are not merely selling merchandise, but rendering 
professional services. But to succeed well in such practice 
of pharmacy as this, the pharmacist must, of course, 
possess the education necessary to command confidence and 
respect as a truly professional man. 

33. No person should enter upon the career of pharmacy 
without full recognition of its responsibilities and the 
courage and conscience requisite to meet those responsibilities 
efficiently and honorably. Human suffering and loss of 
life are involved. A few illustrations will suffice to 
emphasize this. 

We have already pointed out that some of the most valu- 
able remedies known to the physician are deadly poisons. 
Such remedies are often employed in heroic doses, as large 
as the patient can bear, when no other course gives any 
promise of saving life. If in such a case the medicine 
dispensed is much above or much below the prescribed 
standard of strength, the patient's life will probably be 



PHARMACEUTICAL EDUCATION 17 

sacrificed either from an overdose, or for want of a sufficient 
dose to produce the desired result. Diluted hydrocyanic 
acid is such a remedy. It should be of two per N cent 
strength. But it is often found to be of less than one per 
cent strength, and is sometimes found in the market of 
three or four per cent strength. It is the pharmacist's 
duty to test it, to know its actual strength, and to govern 
himself accordingly. 

Extract of Calabar bean is a deadly poison. Heroic doses 
of it are sometimes administered as a last resort to save life 
in cases of lockjaw. But the preparation is made in two 
different ways. Made with strong alcohol it is four times 
as poisonous as when made with diluted alcohol. It is the 
duty of the pharmacist to know what kind to dispense, to 
examine the manufactured product so as to determine which 
kind it is, and to be governed by the facts. 

Digitalis is an extremely valuable drug and numerous 
sufferers have been relieved by it. But it is very sensitive 
and rendered valueless by age or want of care in its 
preservation. It is the pharmacist's duty to have as fresh 
digitalis as the season permits, to preserve it as carefully as 
possible, and to notify the physician if unable to furnish a 
drug which he knows to be in proper condition. 

Unless the pharmacist possesses that education which 
enables him to know his duty, and will faithfully perform 
that duty as he sees it, he fails to carry out his part of the 
contract between him and the people, by virtue of which he 
acquired the right to practice his profession. 

Test Questions 

To the Student: 

Before you begin to answer these Test Questions, read those parts 
of the Student's Guide which relate especially to the preparation of 
the recitation paper. Be sure that your paper corresponds in form 



18 A CORRESPONDENCE COURSE IN PHARMACY 

to that prescribed in the Student 1 s Guide. By so doing you will aid 
your instructors materially and save yourself the possibility of delay. 

Study the question thoroughly before you begin to write your 
answer and then as far as possible put your own thoughts into your 
own words. Never use the language of the text-book unless you are 
specifically requested to do so. 

Execute your papers as neatly as possible and arrange the leaves 
in proper order, as directed in the Student's Guide. Be particular in 
language, spelling, capitals and punctuation, for in all these respects 
your instructor will mark your paper. This is done not for the pur- 
pose of making your work more difficult, but because every pharma- 
cist should be able to write intelligently and correctly. 



1. Why are pharmacists and no others permitted to sell 
poisons ? 

2. A certain medicinal preparation is composed of 
alcohol, water, sugar, strychnine, quinine and iron. Which 
of these substances belong to the materia medica and which 
to the materia pharmaceutica ? 

3. Which of the following substances are inorganic and 
which are organic: Paper, clay, water, wood ashes, snow, 
diamond, amber, coal oil, soap, rubber? 

4. What special technical work belongs exclusively to the 
pharmacist ? 

5. What is meant by Galenical preparations ? 

6. What is the difference between an officinal drug and an 
official one? 

7. What are the main objects of pharmacy laws ? 

8. What are the respective public responsibilities of 
proprietors, clerks and apprentices in the retail drug business 
under the pharmacy laws ? 

9. Why is a good working knowledge of analytical 
chemistry necessary to the pharmacist for his own pro- 
tection as well as for the protection of his customers ? 

10. Why is a knowledge of botany and microscopy 
necessary in pharmacy ? 



LESSON TWO 

To the Student: 

Your last lesson was composed largely of definitions and of intro- 
ductory statements concerning the position and responsibility of the 
pharmacist. With this second lesson you begin the study of the 
important principles upon which all pharmaceutical operations are 
based. You are now dealing with physics and chemistry. 

While your text contains all that is essential on these subjects, yet 
your understanding will be more complete if you can find the time to 
read other authorities. If you have a high school text-book in physics 
such as that of Carhart & Chute, or one in chemistry such as Remsen's 
or Oldberg's, it will be very profitable for you to read in each what is 
said on the topics mentioned in this lesson. If you have previously 
studied physics and chemistry in the high school or elsewhere, review 
such portions of those branches as are alluded to here. While the 
great merit of this course is that it contains those things which are 
essential to a pharmacist, yet a broader knowledge is always an 
advantage to the person who has time to secure it. 

Do not be content with learning what this book says. Constantly 
apply the knowledge you gain. Keep watch for illustrations of the 
principles that are given here. Think while at work of what you 
have learned and you will find these principles continually reap- 
pearing. No experiments are here called for, and you will not be 
required to report on any. Still, no better practice can be had by 
an aspiring young pharmacist than what he can get out of his 
endeavors to demonstrate the truth of statements made to him or to 
apply in his daily work the definitions and principles he learns. 
Oftentimes you may find statements that do not appear credible to 
you, or whose real meaning does not seem apparent at once. If, 
however, you try to find applications of the law or proofs of its 
verity, you will succeed easily. In this lesson, for instance, you are 
told, " The quantity of matter in the universe is constant; it cannot 
be increased or diminished." How is that? Does not fire destroy 
wood and lessen the quantity of matter? Certainly not. Ashes, 
water and gases form and the wood becomes something else, but no 

19 



20 A CORRESPONDENCE COURSE IN PHARMACY 

matter is really destroyed. Study to understand, not merely to 
remember 

In the lesson you will find mentioned many elements or substances 
with which you are familiar, and doubtless many„others previously 
unknown to you. In the latter case, fix the names in your mind, 
and in your reading of newspapers and magazines watch for anything 
that relates to them. You will be surprised to see how frequently 
you will find these articles mentioned. Your study has already 
broadened your field of interest. 

But the essential thing for you is to get the pharmacist's view and 
the pharmacist's knowledge. This you will obtain by mastering just 
what is contained in the chapters that compose the lesson. 



Ill 

About Matter and Energy 

34. All medicines consist of matter. 

The human body and all its parts and contents are also 
made up of matter. 

35. All things and phenomena perceptible to our bodily 
senses are either matter or changes in matter. 

36. Physical Bodies are the things of nature which consist 
of matter. 

Earth, air and water, as well as the bodies of all plants 
and animals, are composed of matter. 

37. Matter is that which occupies space and is affected by 
gravitation and subject to motion. 

38. Whatever occupies space is matter; and whatever 
does not occupy space is not matter. 

Each individual particle of matter, however small or large, 
occupies its own space to the exclusion of every other 
individual particle of matter. 

This property of matter is called its impenetrability. 

39. The volume of a body is the space occupied by it. 



ABOUT MATTER AND ENERGY 21 

40. All physical bodies in the universe are apparently 
attracted to and by each other, and this apparent mutual 
attraction which operates between all bodies in nature is 
called gravitation. 

The power with which bodies of matter mutually attract 
each other is in direct ratio to their masses and in inverse 
proportion to the squares of their distances from each 
other. 

41. Weight is the measure of the force by which the earth 
attracts toward its center other bodies of lesser mass. 

Weight manifests itself by the power required to lift any- 
body of matter from a lower to a higher position, and by the 
pressure exerted by an uplifted body upon any support 
which prevents it from falling. 

42. Whatever has weight or is affected by gravitation is 
matter; and whatever has no weight cannot be matter. 

43. The mass of any physical body is the actual quantity 
of matter contained in it, irrespective of the space it 
occupies and irrespective of its weight. 

Two or more bodies may have the same mass and yet 
occupy widely different extents of space ; or they may have 
equal volumes although their respective masses vary 
greatly. 

The relative masses of different bodies may be approxi- 
mately measured by weight. Bat the mass of any particular 
body is a positive magnitude unaffected by its relations to 
other bodies or by any form of energy, whereas the weight 
of any material body varies according to its distance from 
the earth's center. 

44. The relation of the mass of a body to its volume is 
called its density. 

Of two . bodies having the same volume, that having the 
greater mass has, therefore, also the greater density. 

A cubic inch of iron weighs more than a cubic inch of 



22 A CORRESPONDENCE COURSE IN PHARMACY 

water because the density of iron is greater than that of 
water. 

Of two bodies having the same mass but of different 
volumes, that having the smaller volume possesses, there- 
fore, the greater density. 

Whenever any two bodies have the same density their 
relative volumes correspond to their relative masses; there- 
fore, if their masses are equal their volumes are also 
equal. 

45. One of the general properties of matter is inertia. 

By inertia is meant the inability of matter to move with- 
out the impulse called energy, and its inability of its own 
accord to stop its own motion when once started. 

Matter is accordingly altogether passive. 

46. Motion is a change of place or position. 

The idea of motion is inseparable from the idea of that 
which is moved, and that which is moved is matter. 
All matter is in motion. 

47. Energy is the power which acts upon, and in, and 
through matter, causing or preventing changes in its 
position, form, condition and properties. 

Gravitation is not caused by matter, but it is one of the 
effects of energy upon matter. 

48. Energy is indestructible. 

The quantity of energy in the universe is constant. It 
cannot be added to nor diminished. 

49. All of man's knowledge concerning energy must be 
derived from his observation of its effects upon matter. 
Hence man cannot know what energy is, but only what it 
does. 

50. Since all the knowledge we may acquire concerning 
energy must ever be based upon what we learn of its mani- 
festations in the world of matter, and since these mani- 
festations are infinitely varied, they must be classified for 



ABOUT MATTER AND ENERGY 23 

purposes of study and comparison according to our observa- 
tion and conception of their nature. 

Various forms of energy are, therefore, recognized. 

Gravitation, cohesion, adhesion, heat, light, electricity, 
and chemical energy are different forms of energy. 

But any form of energy can be converted into any other 
form of energy; and whenever energy in one form dis- 
appears, its exact equivalent in another form takes its place. 
From this it may be seen that there is but one universal 
energy, and that its quantity is unchanged although its 
modes of manifestation are various, according to the kind 
and condition of the matter upon which it acts. 

51. Matter and energy are inseparable in the sense that 
all matter is actuated by or endowed with energy, and that 
energy is known only through matter. Yet, matter is not 
energy and energy is not matter ; one cannot produce the 
other, nor can one be converted into the other. 

52. Matter, like energy, is indestructible in the sense 
that it cannot be annihilated. 

The quantity of matter in the universe is constant. It 
cannot be increased nor diminished. 

Nearly all kinds of matter may be converted into other 
kinds of matter by various means; but whenever matter is 
changed as to its kind, or chemical structure, its mass 
remains nevertheless unchanged. 

53. The various different forms of energy and motion 
may be communicated or transmitted from one particle or 
body of matter to another. 

54. Work is the application of energy resulting in changes 
in the position or motion of matter. 

Work is always the result of energy and all energy has the 
power to perform work. 

Potential energy is stored-up energy — energy not perform- 
ing work but capable of performing work when released or 



24 A CORRESPONDENCE COURSE IN PHARMACY 

when the causes which prevent it from doing work are 
removed. It is energy prevented from performing work 
by an equal quantity of energy operating in opposition 
to it. 

Kinetic energy is energy of motion or energy in the act of 
performing work. A cannon ball fired at high velocity 
acquires the power of overcoming great resistance. This 
power is its kinetic energy. 

55. Energy does not act in the same manner upon all kinds 
of matter. All matter offers more or less resistance to the 
action of energy, and the amount of resistance offered by 
matter is according to its kind. Moreover, different 
individual kinds of matter appear to possess the property 
of qualifying the operation of energy through them. Thus 
one form of energy may be changed into another form of 
energy according to the kind of matter upon or through 
which it acts ; as heat into mechanical action in the steam 
engine, and mechanical action into light and heat as in the 
production of electric light. In fact, different kinds of 
matter are recognized according to their behavior in respect 
to energy, for the specific properties of any individual kind 
of matter are its relations to energy. 

56. From the observed respective attitudes and behavior 
of bodies of matter toward each other when acted upon by 
different forms of energy, it is evident that one form of 
energy may act in direct opposition to another form of 
energy. Energy may cause certain particles of matter to be 
apparently attracted by and to each other, while it causes 
certain other particles of matter apparently to repel each 
other. 

Energy, therefore, manifests itself in two opposite 
modes — attraction and repulsion. 
Attraction and repulsion co-exist. 



THE DIVISIBILITY AKD COMPOSITION OF MATTER 25 
IV 

The Divisibility and Composition of Matter 

57. The wonderful divisibility of matter is exemplified by 
numerous phenomena, such as the property of various kinds 
of colored substances to impart their color to enormous 
quantities of water or other solvents, the property of 
odorous substances to perfume the air, and that of the most 
minute quantities of various substances to reveal their 
presence by chemical tests. 

58. Countless kinds of matter exist. Numerous kinds 
are known, and substances before unknown are being dis- 
covered or produced in practically endless variety. 

59. All kinds of matter may be classified into: 1, 
elemental matter, and 2, compound matter. 

60. Elemental matter is matter which cannot by any 
known means be decomposed or separated into other kinds 
of matter, nor produced by combining together any other 
kinds of matter. 

One kind of elemental matter cannot be transmuted into 
any other kind of elemental matter. 

61. About eighty distinct kinds of elemental matter are 
believed to be now known (1904). There are strong reasons 
for "believing that still other kinds of elemental matter are 
in existence which may yet be discovered. At the same 
time it is not impossible that one or more of the kinds of 
matter now recognized as elemental may be found to be 
decomposable or compound matter. 

It is also believed to be possible that some substances now 
regarded as distinct individual kinds of elemental matter may 
be found to be simply different forms of but one kind of mat- 
ter. Finally, it is believed possible, if not probable, that all 
matter is one, and that the different kinds of elemental matter 
called the chemical elements are but the various forms which 



26 A CORRESPONDENCE COURSE IN PHARMACY 

the one matter assumes under different conditions. But the 
oneness of matter, should it be demonstrated to be a fact, will 
not do away with the conception of the distinct kinds of 
simple matter now called elements, but will only modify it. 

62. About three -fourths of the known elements are the 
so-called metals. 

Iron, copper, lead, tin, zinc, nickel, gold, silver, platinum, 
aluminum and mercury are familiar examples of metals or 
metallic elements. 

63. About one-fourth of the known elements are called 
non-metallic elements, or not-metals. 

Sulphur, carbon, phosphorus, chlorine, bromine, iodine, 
oxygen, nitrogen, hydrogen, and silicon are non-metallic 
elements. 

64. All matter consists of indivisible and therefore unde- 
composable particles called atoms. 

An atom is consequently the smallest particle of any 
element that can enter into the formation of any kind of 
compound matter. 

There are, of course, as many distinct elements as there 
are different kinds of atoms, and no more. 

65. About one-half of the distinct kinds of atoms or 
distinct elements now believed to be known are of rare 
occurrence in nature. Of the more widely distributed 
elements occurring in large quantities, oxygen and silicon 
are the most abundant. 

66. Very few of the elements exist in nature uncombined 
with other elements. 

But oxygen, nitrogen, carbon, sulphur, silver, and copper 
occur both combined and uncombined with other elements ; 
and gold, platinum, argon, krypton, and some. other elements 
occur in nature only in their free or uncombined state. 

67. Under ordinary conditions atoms rarely exist singly 
or detached from other atoms. They are found almost 



THE DIVISIBILITY AND COMPOSITION OF MATTER 27 

invariably united in groups of two or more. This union 
of atoms into groups is governed by fixed laws. 

Some recently discovered gaseous elements, including 
argon and krypton, contained in the atmosphere, consist 
of particles which are evidently single atoms. At very 
high temperatures the vapors of the elements called 
chlorine, bromine, iodine, mercury, cadmium and zinc 
also consist of monatomic particles. 

68. Molecules are the smallest particles into which any 
particular kind of matter can be divided without losing the 
specific properties which determine its individuality. A 
molecule of starch is the smallest particle in which that 
substance can exist as starch. When the molecule is broken 
up, the starch is separated into its elemental substances. 

Molecules may consist of one or two or more atoms, and 
molecules containing more than one atom may consist of 
atoms of but one kind, or of atoms of different kinds. 

Molecules consisting of single atoms (monatomic mol- 
ecules) must necessarily be elements. 

69. Elemental molecules are molecules consisting of but 
one kind of atoms. 

The eighty chemical elements, or the several kinds of 
elemental matter, consist of elemental molecules. 

70. Compound matter is matter composed of two or more 
elements united together into one or more kinds of atomic 
groups held together in certain definite proportions. Com- 
pound matter can accordingly be decomposed into two or 
more other kinds of matter, and can be, either directly or 
indirectly, composed out of, or produced by combining 
together, two or more other kinds of matter. 

71. Each distinct or individual kind of compound matter 
is called a chemical compound. 

Among the familiar examples of chemical compounds are 
water, common salt, sugar,, alum, borax, quartz, lime, 



28 A CORRESPONDENCE COURSE IN" PHARMACY 

washing soda, baking soda, cream of tartar, green vitriol, 
blue vitriol, flint, chalk, iron rust, alcohol, glycerin, 
quinine, carbonic acid gas, camphor, ether, chloroform, and 
oxides, acids and salts of all kinds. 

72. Compound molecules are molecules composed of more 
than one kind of atoms, or of two or more elements, held 
together in definite proportions in accordance with the laws 
of atomic combining value, called valence. 

All the innumerable different kinds of matter in the 
world are made up of the relatively extremely small 
number of chemical elements. 

73. All atoms of any one kind have the same mass and 
in all respects the same properties. 

74. All molecules of any one kind have the same mass, 
the same composition and structure, and in all respects 
the same properties under the same conditions. 

75. Atoms and molecules are so minute that they cannot 
singly be rendered visible by any known means. 

It has been stated that it takes 8,000,000,000 molecules 
of water to make a particle of sufficient size to be seen by 
the aid of one of the best modern microscopes. 

76. The relative masses of different kinds of atoms, called 
their atomic weights, are known ; but their absolute weights 
are unknown. 

77. The relative masses of molecules, called their molec- 
ular weights, are the sums of the masses of their component 
atoms. 

78. Comparatively few chemical compounds exist in 
nature in a pure condition or unmixed with other kinds of 
matter. Nearly all pure or unmixed chemical compounds 
are produced or separated from other substances by man's 
labor. 

79. The innumerable varieties of matter found in nature 
are generally mixtures of two or more, and usually very 



THE DIVISIBILITY AND COMPOSITION OF MATTER 29 

many, different kinds of chemical compounds in varying 
proportions. 

Earths, soils, wood, flesh, bone, oils, fats, milk, cheese, 
resins, and many other substances having the appearance of 
uniform composition, are nevertheless, chemically considered, 
mixtures or mixed substances because they are made up of 
several kinds of molecules not held together by chemical 
energy nor combined in definite proportions. 

80. A chemically homogeneous substance consists exclu- 
sively of individual particles of identical specific properties 
or of but one distinct kind of matter. 

All chemically homogeneous substances are also physically 
homogeneous. 

81. Physically homogeneous substances are substances of 
uniform appearance and whose least discernible particles 
all have the same composition and properties. Such sub- 
stances may consist of but one kind of matter, elemental or 
compound; but they are in the vast majority of cases 
mixtures, chemically considered. 

Benzine, volatile oils, fixed oils, alloys, solutions, air, the 
yolk of an egg, wines, and numerous other substances which 
appear to be of perfect sameness throughout their whole 
mass are nevertheless mixed substances or mixtures of 
different kinds of matter, or consist, each, of different kinds 
of molecules. 

82. The physical properties of matter are those properties 
which can be observed or discovered by means not involving 
any alteration in its composition or structure. 

The physical properties of any substance belong to any 
number of its particles taken together. They are properties 
perceptible to our physical senses unaided by chemical 
agencies, and include external form, color, odor, taste, 
specific weight, hardness, malleability, ductility, brittleness, 
elasticity, tenacity, adhesiveness, melting point, boiling 



30 A CORRESPONDENCE COURSE IN PHARMACY 

point, solubilities, etc. But while the physical properties of 
matter may be determined or observed without any 
reference to chemistry, they nevertheless depend primarily 
upon the composition and structure of the molecules, or, in 
other words, upon the component elements and the arrange- 
ment of the component atoms. 

83. The chemical properties of matter are those directly 
and exclusively dependent upon and relating to conditions 
within each individual molecule, and discoverable only by 
chemical means. They include the intensity, quality, and 
quantity of the chemical energy actuating the component 
atoms, and the masses, chemical behavior and relative 
stability of the molecules. 

84. No two different kinds of matter have exactly the 
same properties in every particular. 

85. Under the same conditions, any one distinct kind of 
matter has invariably the same properties in every par- 
ticular. 

86. Allotropy. Certain elemental substances occur in 
different forms, with different properties. This is called 
allotropy, and the different forms assumed by the element 
are called its allotropic modifications. 

Carbon, sulphur, phosphorus, and several other elements 
occur in various allotropic modifications. Diamond, the 
black lead or graphite of our lead pencils, and charcoal are 
all one element — carbon. Sulphur occurs in at least four 
distinct modifications which differ in consistence, color, 
solubility and other particulars. Phosphorus is either a 
waxy, white substance which is self -inflammable in the air 
and very poisonous, or a red powder which is neither self- 
inflammable nor poisonous. 

The causes of allotropy are not understood. It is probably 
due to differences in the number of atoms contained in their 
molecules or to differences in the relative grouping of 



THE DIVISIBILITY AND COMPOSITION OF MATTER 31 

those atoms, or to differences in the arrangement of the 
molecules with reference to one another. 



Test Questions 

To the Student: 

Consult the Student's Guide again. Be sure that the form of your 
paper is right. Do not consult your text-book while you are answer- 
ing the questions. Be independent and self-reliant if you really 
mean to become a skillful pharmacist. Keep your paper neat and 
well arranged. Be particular with your writing. No profession 
requires greater accuracy than pharmacy, and accuracy can be made 
a habit. 



1. What is the difference between volume and mass ? 

2. Which has the greater mass, an ounce of cotton or an 
ounce of lead ? 

3. What is the difference between gravitation and weight ? 

4. What is the difference between mass and weight ? 

5. How do we know that energy exists ? 

6. How are different individual kinds of matter dis- 
tinguished from one another ? 

7. Give an illustration of the extreme divisibility of matter. 

8. Into how many distinct kinds of atoms can all the 
substances on the globe be split up, so far as now known ? 

9. About how many different kinds of metals are known ? 

10. About how many different chemical elements are 
known to occur in comparatively common kinds of matter ? 

11. Name some elements that exist in nature in an 
elemental condition. 

12. Name some elements known to exist in nature in an 
atomic condition. 

13. What is the difference between an atom and a 
molecule ? 

14. What is the weight of an atom in grains ? 



32 A CORRESPONDENCE COURSE IN PHARMACY 

15. What is the difference between a physical mixture 
and a chemical mixture ? 

16. Do all atoms have the same weight and the same 
volume without reference to their kind ? 

17. How many different kinds of molecules can be con- 
tained in one chemical compound ? 

18. Are any molecules divisible ? If so, how ? Are any 
molecules indivisible ? 

19. In what particulars may any two molecules of the 
same kind differ from each other in their physical 
properties ? 

20. How is energy produced ? 



LESSON THREE 

To the Student: 

In your previous lesson you learned of the different kinds of 
matter and the general properties of matter. In this lesson your 
attention is called to a number of phenomena of matter generally 
known as changes. You are already familiar with many of these, 
but probably recognize some of them under a different name from 
that given in the text. In your study you should try to find an 
application of and an illustration for each principle and each new 
term presented. As far as you are able to do this, you can feel certain 
that you understand the subject. 



V 

The Important Forms of Energy and Motion Which 
Affect the Condition of Matter 

87. All the individual particles of matter of which any 
physical body consists are mutually attracted to and by 
one another. 

This attraction is called cohesion when it operates between 
molecules all of which are of the same kind, having the same 
mass and identical specific properties. 

It is called adhesion when the individual molecules attracted 
by and held to each other are of two or more kinds. 

Cohesion and adhesion are generally referred to as forms 
of molecular attraction, cohesion operating between like 
molecules, while adhesion operates between unlike molecules. 
But the like individual particles of chemically homogeneous 
substances held together by cohesion are not always true 
single molecules ; they may consist of two or more molecules 

33 



34 A CORRESPONDENCE COURSE IN PHARMACY 

of one or more kinds, as will be explained later on. More- 
over, while it is true that adhesion operates between definite 
individual particles of matter of different kinds, it also oper- 
ates between pieces each consisting of numerous millions of 
such particles, as when two pieces of wood are held strongly 
by and to an intervening layer of glue. Finally, it is evi- 
dent that both cohesion and adhesion are together operative 
in all bodies of mixed matter. 

88. Matter occurs in three different states of cohesion, or 
states of aggregation: 1, the solid; 2, the liquid; and 3, the 
gaseous state. 

But some solids approach the liquid form, some liquids are 
so thick as to be nearly solid ; some substances are semi-fluids 
and others are described as semi-solids. Some liquids are so 
volatile that under ordinary conditions of temperature and 
pressure they easily assume the aeriform or gaseous state. 

Numerous kinds of matter can assume any one of the three 
states of cohesion according to circumstances. But many 
substances are known only as solids ; others only in the liquid 
state ; while others exist in two of the states of cohesion. 

All gases and vapors can probably be condensed into 
liquids and solids by strong enough pressure at a sufficiently 
low temperature ; but not all solids can be converted into 
liquids, and not all liquids can be converted into gases, with- 
out decomposition. 

89. Cohesion (and adhesion), unless overcome by other 
forces, sufficiently resist changes of the relative positions of 
the aggregated particles of solid bodies to enable these to 
retain their shape without external support. Thus cohesion 
(and adhesion) impart hardness, tenacity, and other related 
properties to solids. But the greater solidity of many solids 
is clearly due in part to their physical structure or the 
mechanical effects of the formation of the aggregated parti- 
cles into crystals, fibrous tissues, etc. 



THE IMPORTANT FORMS OF ENERGY AND MOTION 35 

90. A liquid is a substance of such feeble cohesion that it 
has no definite shape of its own, but assumes a conformation 
determined by the containing vessel. Without the support 
of such a vessel the liquid, impelled by its weight, spreads 
outward and downward unless its flow is arrested by obstacles. 

Liquids may be viscid, like castor oil, tar, honey, glycerin, 
or thick mucilage ; they may be mobile, like chloroform or 
ether; they may be heavy, like chloroform and sulphuric 
acid; or light, like ether. 

91. Gases are substances apparently without cohesion? or 
substances in which cohesion is nullified by other forces. 

The air is a mixture of gases, chiefly nitrogen and oxygen, 
and gases are, therefore, frequently described as aeriform. 

92. Distinction is made between gases which can exist as 
such at ordinary temperatures, and substances which assume 
the gaseous state only at higher temperatures. The last 
mentioned are called vapors. 

93. Liquids and gases are called fluids. 

94. Heat is a form or mode of molecular motion. The 
degree of velocity of heat motion is called temperature. 

To heat a substance or to increase its temperature is to 
increase the velocity of the heat motion of its molecules. 

95. Mechanical motion is the motion of molar matter. 
Molar motion can cause independent molecular motion. 
Hence mechanical motion is convertible into heat. Thus 
friction generates heat. Heat motion is also convertible into 
mechanical motion, as may be seen from the applications of 
steam power. 

96. Heat motion may cause molecules. to separate from 
one another; and, when its velocity is sufficient, the atoms of 
which the molecules are composed may also be swung away 
or separated from one another so that the molecules are 
disrupted or decomposed into smaller groups of atoms or 
into single atoms. Heat is, therefore, described as a repellant 



36 A CORRESPONDENCE COURSE IN PHARMACY 

force. But the atoms or groups of atoms separated from 
one another by their heat motion do not mutually repel one 
another. 

97. Atomic motion is the motion of individual atoms 
composing the molecules, and is distinct from molecular 
motion. Yet atomic motion or chemical motion is one of 
the chief causes of molecular motion. 

98. Whenever any two or more elements combine with 
each other to form any chemical compound, heat is gener- 
ated ; and whenever any chemical compound is decomposed 
into its elements, heat energy is consumed or heat motion is 
diminished, or the temperature is depressed. 

99. The effects of heat upon cohesion. 

Many solids and all fluids expand measurably in every 
direction when heated. 

Some solids liquefy when heated to a sufficiently high 
temperature and are then called fusible solids. The tem- 
perature at which any solid fuses is called its fusing point or 
melting 'point. The melting point of any given substance is 
a fixed temperature or a physical constant. But many solids 
are infusible. 

Some infusible substances remain practically unaltered by 
the heat ; others become converted into vapor without first 
melting; and still others are decomposed into other sub- 
stances under the influence of heat. 

The freezing point or congealing point of any substance is 
theoretically identical with its melting point ; practically it 
is only approximately so. 

Solids and liquids which can be converted into vapors are 
described as vaporizable. If they assume the gaseous state 
readily or at comparatively low temperatures they are said 
to be volatile. But some solids and liquids are fixed sub- 
stances; their state of cohesion is fixed or unaltered even at 
very high temperatures while they remain undecomposed. 



THE IMPORTANT FORMS OF ENERGY AND MOTION 37 

The temperature at which any solid or liquid rapidly 
assumes the gaseous state is called its boiling pointy and the 
boiling point of any substance is, under like conditions, 
constant. The condensation point of any substance is nearly 
coincident with its boiling point. 

100. The expansion and contraction of solids and liquids 
under the influence of changes of temperature are not 
uniform or regular. But gases and vapors expand or contract 
equally and uniformly. The volume of any gas is increased 
at the rate of 0.003663 for each degree C. of increased 
temperature, and it decreases at the same ratio as its 
temperature falls. 

101. The power by which any gas resists compression is 
called its vapor tension. 

102. The volume of any gas is inversely proportional to 
the pressure it sustains. This is called Mariotte's law. 

The density of any gas is directly proportional to the 
pressure to which it is subject. 

103. Whenever any given substance expands under the 
influence of heat, the pressure remaining constant, a fixed 
quantity of heat is required to cause and maintain the expan- 
sion ; and whenever contraction takes place that heat energy 
is liberated, or, rather* at once proceeds to do other work. 

When a liquid assumes the state of vapor it absorbs a fixed 
quantity of heat, and that heat is liberated whenever the 
vapor is condensed to the liquid state. 

104. The heat required to expand the volume of any body 
of matter, or to convert a solid into a liquid, or a liquid into 
vapor, is called latent heat, because that heat manifests its 
presence in no other way. The heat which melts ice can- 
not at the same time raise its temperature, and the heat 
which turns water into steam cannot at the same time make 
that steam hotter. Additional heat energy is necessary to 
raise the temperature of the water formed by the melted ice, 



38 A CORRESPONDENCE COUESE IN PHARMACY 

or of the steam formed out of the water, after their forma- 
tion. 

When ice is melted in a vessel placed over a fire, the 
temperature of the water formed out of the ice remains 
constant, 0° C. or 32° F., until all of the solid water has 
been changed to liquid water; afterwards, if the application 
of heat be continued, the temperature of the water rises to 
100° C. or 212° F. and then remains stationary until all of 
the liquid water has become converted into vapor. 

105. The temperature of the water vapor or steam is 100° 
C, no more and no less. But if the steam be confined in a 
boiler or in tubes so that it cannot expand, the pressure 
which opposes the formation and expansion of the vapor 
raises the boiling point because a greater amount of heat 
energy is required to overcome that pressure, and if the 
steam is conducted through iron pipes into a furnace fire the 
steam passing through the pipes may be heated to the same 
temperature as the iron. Steam thus heated is called super- 
heated steam. 

106. Solution is a physically perfectly homogeneous 
intermixture of two or more substances. It is not known 
by what kinds of energy the components of a solution 
are so intimately blended with one another. Both physical 
and chemical energy must be concerned in the phenom- 
ena of solution, for it is now generally admitted that when 
certain soluble substances are dissolved in a sufficiently 
large quantity of water the molecules of the dissolved sub- 
stances are dissociated into their component atoms or groups 
of atoms, each molecule being divided into two parts called 
ions. 

107. Solutions are formed by solids, liquids and gases. 
Thus a homogeneous mixture of gases, such as air, is a 
solution; when camphor evaporates into the air, a gaseous 
solution of camphor in air or of air in camphor vapor may 



THE IMPORTANT FORMS OF ENERGY AND MOTION 39 

be said to be formed ; and when water evaporates, the water 
vapor and the air form a solution with or in each other. 
When camphor and chloral, which are both solids, are 
rubbed together a homogeneous liquid is formed. 

108. But the most commonly accepted definition of solution 
is: the liquefaction of any substance by the action upon it. 
of any liquid, the product being a homogeneous liquid con- 
sisting of the solvent and the dissolved substance. 

This definition recognizes no solution except a liquid 
solution, and no solvent except a liquid solvent, while the 
dissolved substance may have been either solid, liquid or 
gaseous before it was dissolved. 

109. Some substances are quite insoluble in all liquids; 
other substances are soluble in some liquids but insoluble in 
others; and soluble substances may be freely soluble, 
moderately soluble, or only sparingly soluble. 

Solids are generally, but not always, much more readily 
soluble in hot than in cold liquids. Gases are more soluble 
in cold than in hot solvents. The miscibility of liquids, or 
their solubility in each other, is also affected by temperature. 

When solubility is mentioned without naming the solvent, 
it is always the solubility in water that is referred to. 

110. The rate of solubility of any given substance in any 
given solvent is constant under constant conditions. The 
coefficient of solubility of any substance is the number of 
grams of it soluble in 100 grams of water at 15° C. 

111. Water is the most wonderful and useful of all 
solvents. Other common solvents are alcohol, ether, liquid 
hydrocarbons (like benzine), fixed oils (like olive oil), volatile 
oils (like oil of turpentine), and chloroform. 

Water-soluble substances are very numerous and include 
both inorganic and organic substances. 

112. Solids and liquids which attract and absorb water 
from moist air are called hygroscopic substances. 



40 A CORRESPONDENCE COURSE IN PHARMACY 

Hygroscopic moisture is the amount of absorbed moisture 
contained in substances exposed to the air. 

113. Excessively hygroscopic solids which are freely soluble 
in water and which, therefore, attract enough water from 
the air to become liquefied by solution in that water, are 
deliquescent. 

Chlorinated lime, compressed yeast, and glycerin are 
hygroscopic. Caustic potash, zinc chloride, and ferric 
chloride are deliquescent. 

114. The diffusion of liquids into one another, or the 
tendency of any two or more liquids in contact with one 
another to form a perfect solution of uniform composition 
whenever they are mutually soluble in one another, is clearly 
a phenomenon effected by the same cause or causes which 
produce solution. 

The diffusion of gases into each other is also solution. 

115. Light is caused by energy because it can produce 
motion. It is capable of producing striking changes in 
matter and sometimes almost instantaneously, as we know 
from the results of photography. 

Light, like heat, frequently causes the decomposition of 
substances. It is, therefore, necessary to protect from the 
light all medicines and other valuable substances affected 
by it. 

116. That form or manifestation of energy which is called 
electricity possesses enormous power to effect changes in 
matter. Its most striking chemical effects are in opposition 
to chemical attraction, for many substances are decomposed 
by the electric current. 

117. Chemism is that mode of energy by which distinct 
individual kinds of matter are formed or transformed. 

Chemism is also called chemical energy, chemical attrac- 
tion, chemical combining power, chemical affinity, atomic 
attraction, and atomic energy. 



THE IMPORTANT FORMS OF ENERGY AND MOTION 41 

118. The particles of matter which can unite with one 
another by chemical energy to form distinct individual sub- 
stances of definite composition and structure may be either 
atoms or molecules. But the specific properties of chemica? 
compounds formed by the combination of atoms into single 
molecules are radically different from those of their com- 
ponent atoms, while the specific properties of substances 
formed when two or more unlike molecules are held to each 
other, do not, as a rule, differ widely from those of their 
component molecules. 

119. All changes in the composition and structure of 
molecules are chemical changes and are governed by chemical 
energy in accordance with chemical laws of nature. 

The formation, relative stability, transformation and 
decomposition of molecules all depend upon chemism, but 
chemism is decidedly affected by other forms of energy, such 
as heat, light, electricity, and even cohesion and adhesion. 

120. Any and every chemical change is chemical action 
and reaction. 

Among the most familiar examples of chemical action are 
fire, explosions, fermentation, decay, the action of metals 
and many other substances upon acids, and the corrosive 
action of strong lye upon animal and vegetable matter. 

Fire, or combustion, is chemical action accompanied by 
the evolution of large quantities of heat and light. This 
is the chief source of heat available for the use of man. 
When carbon and oxygen unite, heat and light are both 
produced, but in many chemical reactions no light is 
evolved, though heat may be liberated in large quantities. 
If water be poured upon unslaked lime, chemical action 
results, and the mixture grows very hot, but no light is seen. 
The same phenomenon may be noticed when dilute sulphuric 
acid and ammonia water are mixed. Heat indirectly aids 
chemical action. Some reactions are begun only in the 



42 A CORRESPONDENCE COURSE IN PHARMACY 

presence of heat, but after once started the heat generated 
by the reaction is sufficient to keep up the process. It is 
necessary to heat wood or coal to a certain point to compel 
ignition, but once burning, the fire continues as long as coal 
or wood and oxygen are supplied. 

Test Questions 

To the Student: 

Again consult your Student's Guide, so that you will make no 
mistake as to the form and arrangement of your paper. Before 
writing this paper, review carefully the paper on Lesson II. That 
will undoubtedly contain some criticisms and suggestions which 
will assist you in writing your paper on this lesson. You should 
aim to make each paper freer from error and in every way stronger 
than the previous one. Do not consult the text-book while writing. 

Be careful with your penmanship. It is especially important that 
a pharmacist write a neat, legible hand. Your spelling, too, should 
be accurate. A pharmacist easily might be led into serious mistakes 
by errors in spelling. The new words Of these lessons should be 
made a part of your vocabulary at once. Where terms are similar 
be sure to distinguish between them. Accuracy in everything, is the 
pharmacist's motto. 



1. Define cohesion. 

2. What are the effects of adhesion ? 

3. How may cohesion be overcome ? 

4. Under what conditions do cohesion and adhesion 
oppose each other ? 

5. What is meant by a fluid ? 

6. What is the difference between gas and vapor ? 

7. What is the meaning of the word temperature and 
what causes the difference between a high temperature and 
a low temperature ? 

8. Mention several means of producing heat. 

9. Mention some of the effects of heat upon matter. 



THE IMPORTANT FORMS OF ENERGY AND MOTION 43 

10. What is the boiling point of any liquid ? 

11. If a certain gas measures 273 volumes at 20° C, how 
much will it measure at 22° C? 

12. A volume of a certain gas being 1 liter under the 
pressure of 1 atmosphere, what will be its volume under 
the pressure of 2 atmospheres ? 

13. If a given mass of gas occupies 10 cubic centimeters 
at 0° C, how many cubic centimeters will it occupy at 
212° F.? 

14. If a given mass of gas occupies 50 volumes under 760 
millimeters pressure, how many volumes will it occupy under 
756 millimeters pressure ? 

15. One liter of oxygen at 0° 0. and under 760 millimeters 
pressure weighs 1.43 grams. What is the weight of two 
liters of oxygen at 16° C. under 750 millimeters pressure? 

16. One liter of carbon dioxide at 0° 0. under the pressure 
of one atmosphere weighs 1.9657 grams. What is the 
volume of 10 kilograms of 00 2 at 8° C. under a pressure of 
4 atmospheres ? 

17. State the law of Mariotte. 

18. What is meant by latent heat ? 

19. How can steam be heated to 200° 0.? 

20. What form of molecular attraction in a solid must be 
overcome when that solid is dissolved in a liquid ? 

21. How would you aid the solution of a gas in a liquid ? 

22. What is commonly meant by the term solution ? 

23. Does increased temperature always aid solution ? 

24. What is the coefficient of solubility of a substance of 
which 60 grams can be dissolved in 300 grams of water at 15° C? 

25. What are the most common solvents in pharmacy and 
chemistry ? 

26. What is the difference between a hygroscopic and a 
deliquescent substance ? 

27. What is meant by the expression diffusion of gases 9 



44 A CORRESPONDENCE SCHOOL IN PHARMACY 

28. Why is it necessary to protect medicinal substances 
from light ? 

29. Define chemical energy. 

30. Does heat aid or oppose chemical attraction ? 

31. Is chemical attraction aided or opposed by light and 
by electricity? 

32. Which form of attraction will cause the greater 
changes in matter, atomic attraction or molecular attraction ? 

33. What produces combustion ? 



LESSON FOUR 

To the Student: 

The last two lessons have been concerned with the elements of 
physics. We now leave for a time that subject and take up the 
elements of chemistry. The next few lessons treat of the theory of 
chemistry and may seem somewhat obscure at first, but if you will 
read them carefully and weigh each statement, the meaning will 
doubtless appear to you. If the course of reasoning does not then 
seem clear, you can wait with the confident expectation that the 
subject will become clearer in subsequent lessons. Every new sub- 
ject has a vocabulary and language of its own, which for a time is 
difficult to the beginner, but by constant use of the terms he becomes 
familiar with them and is able to reason with greater ease and accu- 
racy. 

It is not expected that you will learn the text verbatim, except in 
the case of certain rules and principles which are italicized to attract 
your attention. Such, for instance, are the Law of Definite Pro- 
portions and Avogadro's Law, both of which you will find stated in 
the sixth lesson. The table of elements given in Section 122 is not 
to be committed to memory, though the names, symbols and atomic 
weights of the principal elements should be familiar. What these 
are you will learn from the frequency with which they are mentioned 
in the text. If you find yourself frequently referring to the table 
for the symbols and atomic weights of any given element, that should 
be sufficient hint to learn the facts relating to that element. 

VI 

The Chemical Elements 

121. The classification of the elements into metals and 
non-metals has been referred to. 

But some elements possessing physical properties character- 
istic of the most pronounced metals have chemical properties 

45 



46 



A CORRESPONDENCE COURSE IK PHARMACY 



such as strikingly characterize non-metallic elements, and a 
few elements partake more or less of the properties of both 
metals and non-metals, physically as well as chemically. 

122. The following list includes the known elements (1905), 
a few of which have been so recently discovered and are so 
rare and costly that their properties have not yet been 
thoroughly studied. 

All elements are represented by specific symbols derived 
from their latinic or other names. These symbols are used 
for the purpose of constructing formulas representing the 
composition and structure of chemical compounds. 

The names of the most important elements contained in 
common substances, including those of medicinal value, are 
printed in heavy-faced type. The others are comparatively 
rare or economically unimportant. The names in the 
second column are in most cases coined words which are not 
Latin but simply latinic in form. 

TABLE OF THE CHEMICAL ELEMENTS WITH THEIR 
ATOMIC WEIGHTS 

•>& •% Elements thus marked are both physically and chemically non- 
metallic. 
•£• Elements which exhibit some of the physical properties of 
metals but which resemble the non-metallic elements in their 
chemical behavior. 
+ Elements which are both physically and chemically metallic in 
their properties and behavior. 
Elements which are not known to enter into any chemical com- 
bination are printed in italics. 









Approximate 


Common Name. 


Latinic Name. 


Symbol. 


Relative Weight 

of the Atom. 
(Atomic Weight.) 


Aluminum + 


Aluminum 


Al 


27 


Antimony •>£• 


Antimonum or 








Stibium 


Sb 


120 


Argon 


Argonum 


A 


39? 


Arsenic •>& 


Arsenum 


As 


75 


Barium + 


Barium 


Ba 


137 


Beryllium + 


Beryllium 


Be 


9 



THE CHEMICAL ELEMENTS 



47 



TABLE OF THE CHEMICAL ELEMENTS— Continued. 



Common Name. 



Latinic Name. 



Symbol.. 



Approximate 
Relative Weight 

of the Atom. 
(Atomic Weight.) 



Bismuth + , 
Boron 2g •><• 
Bromine •% •*• 
Cadmium + 
Csesium + 
Calcium + 
Carbon ■% •>£ 
Cerium + 
Chlorine ■& •% 
Chromium + 
Cobalt + 
Columbium + 
Copper + 
Erbium + 
Fluorine ■*■ %• 
Gallium + 
Germanium + 
Gold + 
Helium 

Hydrogen •}& •>£• 
Indium + 
Iodine $£■ •& 
Iridium + 
Iron + 
Krypton 
Lanthanum + 
Lead + 
Lithium + 
Magnesium + 
Manganese + 
Mercury + 
Molybdenum + 
Neodymium 4 
Neon 
Nickel + 
Nitrogen •& •& 
Osmium + 
Oxygen •)£ •)£ 
Palladium + 
Phosphorus -)j$ •*• 
Platinum + 
Pollonium + 
Potassium + 
Praseodymium + 



Bismuthum 

Borum 

Bromum 

Cadmium 

Csesium 

Calcium 

Carboneum 

Cerium 

Chlorum 

Chromium 

Cobaltum 

Columbium 

Cuprum 

Erbium 

Fluorum 

Gallium 

Germanium 

Aurum 

Helium 

Hydrogenium 

Indium 

Iodum 

Iridium 

Ferrum 

Kryptum 

Lanthanum 

Plumbum 

Lithium 

Magnesium 

Manganum 

Hydrargyrum 

Molybdenum 

Neodymium 

Neum 

Niccolum 

Nitrogenium 

Osmium 

Oxygenium 

Palladium 

Phosphorus 

Platinum 

Pollonium 

Potassium or Kali 

Praseodymium 



Bi 
B 
Br 
Cd 

Cs 

Ca 

C 

Ce 

CI 

Cr 

Co 

Cb 

Cu 

Er 

F 

Ga 

Ge 

Au 

He 

H 

In 

I 

Ir 

Fe 

Kr 

La 

Pb 

Li 

Mg 

Mn 

Hg 

Mo 

Nd 

Ne 

Ni 

N 

Os 

O 

Pd 

P 

Pt 

Po 

K 

Pr 



208 

11 

80 
112 
133 

40 

12 
140 

35.5 

52 

59 

94 

63.5 
166 

19 

70 

72 
197 
4 
1 
114 
126.5 
193 

56 

82 

138 

207 

7 

24.5 

55 
200 

96 
143 

20 

58.5 

14 
191 

16 
106 

31 

195 

? 

39 
140.5 



48 



A CORRESPONDENCE COURSE IN" PHARMACY 



TABLE OF THE CHEMICAL ELEMENTS— Continued. 









Approximate 


Common Name. 


Latinic Name. 


Symbol. 


Relative Weight 

op the Atom. 
(Atomic Weight.) 


Radium + 


Radium 


Ra 


227 


Rhodium + 


Rhodium 


Rh 


103 


Rubidium -f 


Rubidium 


Rb 


85.5 


Ruthenium + 


Ruthenium 


Ru 


101.5 


Samarium + 


Samarium 


Sm 


150 


Scandium + 


Scandium 


Sc 


44 


Selenium %< •>£ 


Selenium 


Se 


79 


Silicon j& 5& 


Silicium 


Si 


28.5 


Silver + 


Argentum 


Ag 


108 


Sodium + 


Sodium or Natrium 


' Na 


23 


Strontium + 


Strontium 


Sr 


88 


Sulphur •% X 


Sulphur 


S 


32 


Tantalum + 


Tantalum 


Ta 


183 


Tellurium $£ 


Tellurium 


Te 


127 


Terbium + 


Terbium 


Tb 


160 


Thallium + 


Thallium 


Tl 


204 


Thorium + 


Thorium 


Th 


233 


Tin + 


Stannum 


Sri 


118.5 


Titanium + 


Titanium 


Ti 


48 


Tungsten + 


Wolframium 


W 


, 184 


Uranium + 


Uranium 


U 


240 


Vanadium + 


Vanadium 


V 


51.5 


Xenon 


Xenum 


X 


128 


Ytterbium + 


Ytterbium 


Yb 


173 


Yttrium + 


Yttrium 


Yt 


89 


Zinc + 


Zincum 


Zn 


65.5 


Zirconium + 


Zirconium 


Zr 


90.5 



All the elements marked with 5K- or with X % can combine 
directly with hydrogen. They are chemically non-metallic 
elements. Elements marked + do not combine directly with 
hydrogen, although some of them form alloys with it. 

Neon, argon, krypton and xenon are gaseous elements 
recently discovered in the atmosphere; all efforts so far 
made to cause these elements to enter into chemical 
combination with any other elements have been unsuc- 
cessful. 

Oxygen and fluorine combine with hydrogen but not with 
each other. All elements can be directly united to oxygen 



THE CHEMICAL ELEMENTS 49 

except fluorine and the four elements named in the preced- 
ing paragraph. 

123. State of Cohesion of the Elements. All of the ele- 
ments enumerated in the preceding table are solids at 
ordinary temperatures, with the following exceptions : Mer- 
cury and bromine are liquids; argon, chlorine, fluorine, 
helium, krypton, neon, nitrogen, oxygen, xenon and hydro- 
gen are gases. 

124. Colors of the Elements. The metals are generally 
opaque and white with or without a hue of grayish, bluish 
or reddish; but gold is yellow, barium and calcium are 
yellowish, copper is reddish. Bismuth displays variegated 
hues of purplish, while its general color is reddish-white. 

Of the non-metallic elements boron is black; carbon is 
either black, as in coal and graphite, or colorless, as in 
diamond; iodine is purplish-black; phosphorus is a White 
waxy substance or a dark red powder; selenium, red or 
black; silicon, brown or gray; sulphur, pale yellow, amber, 
dark brown, or nearly milk-white; bromine is a brown-red 
liquid; hydrogen, oxygen, nitrogen, argon, krypton, neon 
and xenon are colorless gases; chlorine is a greenish gas; 
and fluorine greenish-yellow. 

125. Luster. All the metals possess a peculiar luster which 
in many cases can be greatly heightened by polishing. 

The only non-metallic elements that have a luster approach- 
ing that of metals are iodine in crystals and carbon in the 
form of graphite. The luster of the diamond is quite 
different from and far surpasses that of the metals. 

126. The non-metallic elements never possess tenacity, 
ductility or malleability. Most of the metals exhibit one or 
the other of those properties. 

127. Density. The specific weights of the five metals 
called lithium, sodium, potassium, rubidium and cassium 
range from 0.6 to 1.5; those of the metals called beryllium, 



50 A CORRESPONDENCE COURSE IN PHARMACY 

magnesium, calcium, strontium and barium from 1.6 to 4; 
and those of the metals aluminum, scandium, yttrium, titan- 
ium and zirconium from 2.5 to 4. The specific weights 
of all other metals are higher than 5, ranging from 5.5 to 
22.42. 

The specific weights of all physically non-metallic elements 
are below 5. 

128. Fusibility. All metals are fusible. Of the non- 
metallic elements one is liquid and ten are gases. Sulphur, 
selenium, phosphorus and iodine are readily fusible. Carbon, 
boron and silicon are infusible. 

129. Volatility. Of the physically metallic elements only 
mercury, potassium, sodium, magnesium, zinc, cadmium and 
arsenic may be readily distilled; and antimony and tellu- 
rium can be distilled with a current of hydrogen. 

The non-metallic elements that are not gaseous at ordinary 
temperatures can all be readily vaporized except carbon, 
boron and silicon. 

130. Solubility in common solvents. All metals are 
absolutely insoluble in water, alcohol, ether, chloroform, 
glycerin, benzin, carbon disulphide, volatile oils and fixed oils. 

Chlorine and iodine are slightly soluble in water ; bromine 
more so. Iodine is soluble in alcohol, glycerin, chloroform, 
liquid hydrocarbons, carbon disulphide, volatile oils and fixed 
oils. Phosphorus is soluble in chloroform, ether, absolute 
alcohol, carbon disulphide and fixed oils. Sulphur dissolves 
in chloroform, benzine, carbon disulphide, oil of turpentine 
and fixed oils. 

131. Metals are usually good conductors of heat and of 
electricity. The non-metallic elements are very feeble con- 
ductors. 

132. Chemical behavior of metals and non-metals. The 
metals form various solutions and alloys with each other. 
Gold and several other metals dissolve in mercury at ordinary 



THE CHEMICAL ELEMENTS 51 

temperatures. Many metals can be dissolved in each other 
when melted. Sometimes the combinations effected may be 
crystallizable bodies containing the component metals , in 
definite proportions corresponding to their atomic weights. 
But these combinations or alloys are decidedly metallic, 
retaining in a high degree the characteristics of the metals 
of which they are constituted. Hence it may be concluded 
that the combinations formed by the metals with each other 
are not true chemical compounds, but only solutions. 

The compounds formed by non-metallic elements with 
each other or with metals are strikingly different. They are 
countless, and they rarely resemble in any respect or degree 
their component elements. Thus the reddish metal copper 
combines with the colorless gas oxygen, forming a black 
powder called copper oxide; the brilliant, silver-white, liquid 
metal mercury combines with the colorless oxygen to form a 
red, or yellow, or black oxide, and with yellow sulphur to 
form a red or a black sulphide ; sulphur combined with its 
own weight of oxygen forms a colorless gas of an irritating 
odor, but with one and one-half times its weight of the 
gaseous oxygen it forms an odorless white solid; the three 
colorless gases nitrogen, hydrogen and oxygen form a white 
solid called ammonium nitrate; and the elements carbon, 
hydrogen, oxygen and nitrogen form innumerable compounds 
of a great variety of properties. 

Test Questions 

It will probably not be necessary for us to call your attention again 
to the form of your paper. Let it be understood that unless you are 
specifically directed to change your plan, you are to continue in that 
which has been prescribed for you. If the questions seem to call for 
any explanation, you will find that explanation at the beginning of 
the questions. 

1. About how many metals are known and about how 
many non-metallic elements ? 



52 A CORRESPONDENCE COURSE IN PHARMACY 

2. What are the symbols for lead, antimony, mercury, 
potassium, silver, sodium and tin ? 

3. What is the difference between a chemically metallic 
element and a chemically non-metallic element ? 

4. Mention six elements which at ordinary temperatures 
are gases. 

5. What elements are liquid at ordinary temperatures ? 

6. Mention the most striking- physical properties by which 
metals differ from non-metallic elements. 

7. Do you know of any non-metallic elements having 
specific weights between 6 and 10 ? 

8. Can you mention some non-metallic elements which 
are not fusible ? 

9. Mention some that are not volatile. 

10. Are any of the metals soluble in each other, and if 
so, what are such solutions called ? 

11. How many of the metals combine chemically with 
oxygen ? How many of them combine with hydrogen ? 

12. How many of the non- metallic elements combine with 
oxygen and how many of them with hydrogen ? 






LESSON FIVE 

To the Student: 

Considerable attention has been given in this lesson and others 
that follow to elaborating for you the course of reasoning by which 
certain laws were established. It is thought that everything has been 
made sufficiently clear, but it is too much to expect that you will be 
able to follow the reasoning at first reading. We expect that you 
will have to go many times over the text, until not only the words 
become familiar to you in their meaning, but the trend of thought 
becomes as natural to you as it is to the writer. Do not forget your 
dictionary or the treatment of corresponding subjects in the school 
text-books. All will help you to a clearer understanding of the text. 



VII 

Definite Combining Proportions and the Atomic 
Hypothesis 

133. Proust pointed out that all chemical compounds 
contain their component elements in fixed and invariable 
proportions. The following examples illustrate this : 

a, 1 gram of hydrogen unites with 16 grams of oxygen to 
form the compound called hydrogen dioxide, commonly 
known as peroxide of hydrogen. These proportions can- 
not be altered. And a mass of 17 grams of hydrogen 
dioxide always consists of 1 gram of hydrogen and 16 grams 
of oxygen. 

A 2-gram mass of hydrogen unites with a 16 -gram mass 
of oxygen to form the compound called water. And all 
water, wherever found or however produced, when de- 
composed yields hydrogen and oxygen in the proportion 

53 



54 



A CORRESPONDENCE COUKSE IN" PHARMACY 



of 1 part of the first named to 8 parts of the other 
element. 

1). 1 gram of hydrogen unites with 35.5 grams olthe 
element called chlorine to form 36.5 grams of hydrogen 
chloride, commonly called hydrochloric acid gas. 

In the following table are given in grams the combining 
proportions of several different elements and the product 
obtained from the combination. Eead from left to right, 
the first and third columns give the names of the elements ; 
the second and fourth, their combining weights; the fifth, 
the name of the product ; and the sixth, the weight of the 
product. The horizontal lines separate the compounds into 
related groups : 



Element 


No. OF 
Grams 


Element 


No. OF 
Grams 


Product 


Grams in 
Product 


Nitrogen 

Nitrogen 
Nitrogen 

Nitrogen 
Nitrogen 
Nitrogen 


14 

2x14 
14 

2x14 
2x14 
2x14 


Hydrogen 

Oxygen 
Oxygen 

Oxygen 
Oxygen 
Oxygen 


3 

16 
16 

3x16 
2x16 
5x16 


Hydrogen Nitride 

(Ammonia) 
Hyponitrous oxide 
Mononitrogen mon- 
oxide (nitrosyl) 
Nitrogen trioxide 
Nitrogen peroxide 
Nitrogen pentoxide 


17 
44 

30 

76 

60 

108 


Nitrogen 


14 


Chlorine 


3x35.5 


Nitrogen trichloride 


120.5 


Manganese 


55 


Chlorine 


2x35.5 


Manganous chloride 


126 


Manganese 
Manganese 
Manganese 


55 

2x55 

55 


Oxygen 
Oxygen 
Oxygen 


16 
3x16 
2x16 


Manganous oxide 
Manganic oxide 
Manganese dioxide 


71 

158 

87 


Carbon 
Carbon 


12 
12 


Oxygen 
Oxygen 


16 
2x16 


Carbon monoxide 

(Carbonyl) 
Carbon dioxide 


28 
44 


Carbon 


12 


Hydrogen 


4x1 


Methane (marsh gas) 


16 


Carbon 


12 


Sulphur 


2x32 


Carbon disulphide 


76 


Sulphur 
Sulphur 


32 
32 


Oxygen 
Oxygen 


2x16 
3x16 


Sulphur dioxide 
Sulphur trioxide 


64 

80 


Sulphur 


32 


Manganese 


55 


Manganese sulphide 


87 



PKOPOKTIOtfS AND THE ATOMIC HYPOTHESIS 



55 



Element 


No OF 
Grams 


Element 


No. OF 

Grams 


Product 


Grams in 
Product 


Sulphur 


32 


Mercury 


200 


Mercuric sulphide 


232 


Mercury 
Mercury 


200 
2x200 


Oxygen 
Oxygen 


16 
16 


Mercuric oxide 
Mercurous oxide 


216 
416 


Mercury 
Mercury 


200 
200 


Chlorine 
Chlorine 


35.5 
2x35.5 


Mercurous chloride 
Mercuric chloride 


235.5 
271 


Sulphur 


32 


Chlorine 


4x35.5 


Sulphur tetrachlo- 
ride 


174 


Carbon 


12 


Chlorine 


4x35.5 


Carbon tetrachloride 


154 



From the foregoing facts, which have been determined by 
repeated experimentation, it appears that the relative com- 
bining masses of the several elements are simple multiples of 
definite values. 
The relative combining mass of hydrogen is 1 or a multiple of it. 

oxygen is 16 

chlorine is 35.5 

nitrogen is 14 

manganese is 55 

carbon is 12 

sulphur is 32 

mercury is 200 

These comparisons might be extended to include every 
chemical compound known, with the same results — definite 
combining proportions by weight of all the different elements 
in all the compounds which they severally form with one 
another. 

134. The combining proportions of hydrogen and chlorine 
whenever they unite to form hydrogen chloride are invariably 
as 1 part of hydrogen to 35.5 parts of chlorine, or 35.5 times 
as much chlorine as hydrogen by weight. Hydrogen and 
chlorine cannot be made to combine in any other pro- 
portions. And if a mass of 36.5 kilograms of hydrogen 
chloride be decomposed it will give 1 kilogram of hydrogen 
and 35.5 kilograms of chlorine. 



56 A CORRESPONDENCE COURSE IN PHARMACY 

135. Two hypotheses were formulated by John Dalton to 
express the definite combining proportions of the elements 
as exemplified in the preceding paragraphs : 

A. The Law of Definite Proportions. — Any given chemical 
compound always contains the same component elements and 
in the same mass proportions. 

B. The Law of Multiple Proportions. — Whenever any two 
elements unite with each other in more than one mass pro- 
portion, simple multiples of a fixed mass unit of either unite 
with a fixed mass unit or with multiples of a fixed mass unit 
of the other element. 

Any two compounds containing the same two elements but 
in different proportions have different properties and are differ- 
ent compounds. When the compound contains more than two 
elements the proportions are also equally simple and definite. 

136. The Atomic Hypothesis. Dalton explained the definite 
combining proportions of the elements by adopting the 
ancient hypothesis that all matter is composed of indivisi- 
ble individual particles, and by assuming that all such parti- 
cles of any one element have the same mass but that the 
particles of one element have a different mass from that of 
the particles of any other element: Each element consists 
of indivisible atoms of fixed mass. 

137. If this atomic hypothesis be accepted as true, then 
the fixed chemical combining proportions by weight are 
thereby explained and seen to be the inevitable result of the 
fixed atomic masses. If, on the other hand, the atomic 
theory be rejected, then the fixed combining weights of the 
elements remain unintelligible, for no other sufficient 
explanation thereof has yet been made. 

The atomic hypothesis is a lucid and reliable working 
theory, and the system of chemistry built upon it leads to 
fixed results which may be expected and realized with 
absolute certainty and uniformity. 



PROPORTIONS AKD THE ATOMIC HYPOTHESIS 5? 

All known facts of chemistry agree with the atomic theory. 

138. Atomic Weight. The numbers expressing the rela- 
tive masses of the atoms of different elements are called their 
atomic weights. The unit of expression of atomic weights 
is the mass of the hydrogen atom. The specific atomic 
weight of hydrogen is, therefore, 1 and that of oxygen is 16, 
because an atom of oxygen weighs 16 times as much as an atom 
of hydrogen. The atomic weight of chlorine is 35.5; that 
of nitrogen is 14; that of manganese is 55; that of carbon 
is 12; that of sulphur is 32; and that of mercury is 200. 

The atomic weights are the smallest relative masses of ele- 
ments that can enter into chemical combination with other 
elements. 

A table of the elements and their atomic weights was given 
in Lesson Four, VI, paragraph 122. 

139. Molecular Weight. As all molecules consist of atoms 
and as all atoms have fixed masses, it follows that the mole- 
cule of any given element or chemical compound must also 
have a fixed mass, which is the sum of the masses of the 
atoms contained in it. 

A few elemental molecules consist of single atoms, and the 
molecular weight of any element having monatomic molecules 
is of course identical with its atomic weight. 

The molecule of hydrogen consists of two atoms of hydro- 
gen. Hence, as the atomic weight of hydrogen is 1, its 
molecular weight is 2. 

A molecule of ordinary oxygen contains two atoms. 
Hence, as the atomic weight of oxygen is 16, its molecular 
weight is 32. But there is another form of oxygen called 
ozone, each molecule of which consists of three oxygen atoms ; 
the molecular weight of ozone is, therefore, 48. 

The molecule of water contains two atoms of hydrogen 
and one atom of oxygen; the molecular weight of water is 
accordingly 18. 



58 A CORRESPONDENCE COURSE IN PHARMACY 

140. Vapor Densities. The specific weights of all gases 
and vapors are expressed in nnits of the density of hydrogen. 
The specific weight of hydrogen in the gaseous state, or its 
vapor density, is 1. The vapor density of any other gas or 
vapor is the quotient obtained when the weight of any given 
volume of it is divided by the weight of the same volume of 
hydrogen. 

One liter of hydrogen at 0° 0. weighs 0.09 gm. ; one liter 
of oxygen at 0° C. weighs 1.43 gm. ; a liter of chlorine at 0° 
C. weighs 3.17 gm. ; and a liter of nitrogen at 0° 0. weighs 
1.26 gm. Hence, as the vapor density of hydrogen is 1, 
that of oxygen must be 16, that of chlorine must be 35.5; 
that of nitrogen 14. These numbers coincide with the 
atomic weights ; we shall presently learn why. 

141. Avogadro's Law. Equal volumes of all gases or 
vapors at the same temperature and under the same pressure 
contain the same number of individual particles of matter.* 

Now, as the vapor density of hydrogen is 1 and its atomic 
weight also 1, and as its molecule contains two atoms so that 
its molecular weight is 2, we see that its molecular weight is 
twice its vapor density. 

The vapor density of oxygen is 16, for one liter of it 
weighs 16 times as much as one liter of hydrogen at the same 
temperature and pressure. The molecular weight of oxygen 
is 32, for its molecule contains two atoms and its atomic 
weight is 16. Hence the molecular weight of oxygen is twice 
its vapor density, just as the molecular weight of hydrogen 
is twice the vapor density of that element. The vapor 
density of ozone, however, is not 16 but 24. Why ? Because 
each individual particle or molecule of ozone consists of 



♦This hypothesis is usually expressed as follows: "Equal volumes of all 
gases contain the same number of molecules." But this statement is incon- 
sistent with the definition of the term molecule (IV, par. 68), which refers to 
the smallest particle of any kind of matter, as the molecule. 



PROPORTION'S AND THE ATOMIC HYPOTHESIS 59 

three atoms of oxygen, and as equal volumes of all gases 
contain the same number of individual particles of matter, 
each individual particle of ozone must weigh 24 times as 
much as each individual particle of hydrogen, and as each 
particle or molecule of hydrogen weighs 2, since it consists of 
2 atoms, the individual particle or molecule of ozone must 
weigh 48 and must consist of three atoms of oxygen. It is 
true that, in a way, a molecule of ozone is a triatomic 
molecule of oxygen; it contains only oxygen. But the 
molecule of oxygen is diatomic, and the molecular weight of 
oxygen is 32. 

Below 500° C. the vapor of iodine weighs 126.5 times as 
much as the same volume of hydrogen at the same temper- 
ature and pressure. Hence that iodine vapor must consist 
of diatomic particles, or particles consisting of two atoms 
each. But at 1700° the vapor of iodine has a density of 
only 63.25, or weighs only 63.25 times as much as an 
equal volume of hydrogen at the same temperature and 
pressure; this iodine vapor at 1700° 0. must accordingly 
consist of particles weighing only half as much as the par- 
ticles of iodine vapor below 500° 0. Therefore, the 
particles of iodine at 1700° must contain only one atom 
each instead of two. The question may then be asked: is 
the diatomic particle of iodine its molecule, or is the mon- 
atomic particle its molecule ? The answer must be that the 
molecule of iodine is its atom, and that the molecular 
weight of iodine is identical with its atomic weight, for the 
monatomic particles of iodine are the smallest particles of 
that element exhibiting the specific properties by which the 
individuality of iodine is determined. 

Ferric chloride is a chloride of iron composed of iron and 
chlorine in the proportion of 56 parts of iron to 106.5 parts 
of chlorine. Its vapor at temperatures below 700° weighs 
162.5 times as much as the same volume of hydrogen; this 



60 A CORRESPONDENCE COURSE IN PHARMACY 

corresponds to the formula Fe 2 Cl 6 , and the weight of each 
particle must be 325. But the vapor of ferric chloride at 
1000° C. weighs only 81.25 times as much as hydrogen, 
which proves that the individual particles of the compound 
at that temperature must consist of FeCl 3 . The molecule 
of ferric chloride is, therefore, now represented as FeCl 3 
and the molecular weight is given as 162.5. It was formerly 
represented as Fe 2 Cl 6 and its molecular weight was then, of 
course, put down as 325. It would be confusing to recognize 
two different molecules and two different molecular weights. 
The smaller particle is then adopted as the molecule. The 
double molecule Fe 2 01 6 may be represented as (FeCl 3 ) 2 . 

142. Gay-Lussac's Proposition. — Gaseous elements combine 
in simple volume proportions, and the volumes of the products 
hear simple relations to the volumes of the component elements. 

This conclusion is self-evident from the law of Avogadro 
and Dalton's laws of combining proportions by weight. 

One liter of hydrogen and 1 liter of chlorine combine to 
form 2 liters of hydrogen chloride, because the molecules of 
hydrogen, chlorine and hydrogen chloride are all diatomic, 
or contain two atoms each. 

One liter of oxygen and 2 liters of hydrogen combine to 
form 2 liters of water vapor, because while the molecules of 
hydrogen and oxygen contain two atoms each, the molecule 
of water contains three atoms (=HOH), or is triatomic. 

Three liters of hydrogen with 1 liter of nitrogen must 
produce only 2 liters of ammonia, H 3 N, because while the 
hydrogen and nitrogen molecules are diatomic the molecule 
of ammonia contains four atoms, or is tetratomic. 

143. Specific Heat. The relative quantity of thermal 
energy (heat) required to raise the temperature of a given 
mass of any substance one degree is called the specific heat 
of that substance. 

The specific heat of water is the unit in which the specific 



PROPORTIONS AND THE ATOMIC HYPOTHESIS 61 

heat of any other substance is expressed. Therefore the 
specific heat of water is 1, and it signifies the quantity of 
heat energy required to raise the temperature of one weight 
unit of water one degree. The specific heat of mercury is 
0.0319, because only yMff o as much heat energy is required 
to raise the temperature of mercury one degree as is 
necessary to raise the temperature of an equal quantity of 
water one degree. 

144. The Law of Dulong and Petit. — All atoms have the 
same capacity for heat. This means that it requires exactly 
the same amount of heat energy to raise the temperature of 
any atom of any kind one degree. 

The specific heat of any element is inversely as its atomic 
Weight. 

The product obtained by multiplying the atomic weight of 
any element by its specific heat is a constant number ; it is 
approximately 6.4, and that number is called the atomic 
heat. Hence when 6.4 is divided by the specific heat of any 
element the quotient must be approximately the atomic 
weight of that element. 

The atomic weight of any element can, therefore, be 
approximately deduced from or verified by its specific heat. 
[6.4 -*- 0.0319=200.] 

145. Neumann and Regnault proved that the specific heats 
of compounds are inversely proportional to their molecular 
weights (just as we have seen that specific heats of elements 
are inversely as their atomic weights). 

The sum of the atomic heats of the atoms of any molecule 
is the molecular heat of that molecule. Hence, when the 
molecular heat of any substance is divided by 6.4 the quotient 
is the number of atoms contained in the molecule, whether 
elemental or compound. Molecular weights can, therefore, 
be deduced from or verified by the specific heats of 
substances. 



62 A CORRESPONDENCE COURSE IN PHARMACY 

146. There are, furthermore, other methods by which 
molecular weights can be verified. These methods would be 
wholly out of place in elementary lessons like these, but their 
existence is referred to simply to indicate that the atomic 
theory is amply confirmed by many facts in chemical physics 
which have been discovered and demonstrated independently 
of one another and of the atomic hypothesis itself. * 

Test Questions 

In general, it is not expected that you will refer to your text in 
the preparation of your answers to Test Questions. We have indi- 
cated some things that should be committed to memory. Other 
things should be thoroughly understood. At the same time there 
may be occasions when the use of your text is almost necessary in 
the solution of problems. You may not remember, for instance, 
the numbers which are necessary. Under such circumstances 
you are at liberty to refer to the text of your lesson, but should 
never do so for principles and laws. If you know and understand 
a law you can apply it. The purpose of these test questions is 
to see whether you know and do understand. If you deceive us, even 
unintentionally, you suffer the consequences, for, unless you are per- 
fectly fair with us, we cannot give you the assistance we should like 
to render. It is what you know, not what you can take from a book, 
that we wish to determine. If your papers are not fairly prepared, 
you lose the best part of that for which you paid when you enrolled 
in the School. 

1. If a given chemical compound consists of carbon and 
oxygen and the carbon in it weighs 6 grams, what will be the 
weight of the oxygen ? 

* The atomic hypothesis is subject to doubt and controversy, because recently 
observed facts would seem to prove that atoms are not indivisible. But even if 
it should be conclusively demonstrated that the atoms are divisible into still 
smaller particles (" electrons"), the facts upon which the atomic theory is based 
will, of course, remain unaltered, the atomic weights will be as real as ever, our 
conception of the atomic structure of molecules will not be materially changed, 
and the truth of the law of Dulong and Petit will not be shaken. New discov- 
eries concerning the structure of matter may modify the atomic hypothesis and 
render it clearer, but will not destroy it. 



PK0P0KTI0NS AND THE ATOMIC HYPOTHESIS 63 

2. How much sulphur can be held in combination by 50 
grams of mercury ? 

3. How much chlorine can be held in combination by 27. 5 
grams of manganese ? 

4. How much chlorine can be held in combination by 7 
grams of nitrogen ? 

5. If a mass of 108 grams of a compound of mercury and 
oxygen be decomposed into its constituent elements, how 
much will the mercury weigh and how much will the oxygen 
weigh ? 

6. Formulate the laws of Dalton concerning chemical 
combining proportions. 

7. What is the atomic theory ? 

8. How does it explain the law of multiple proportions ? 

9. What is the molecular weight of any substance? 

10. What would you call the minimum relative mass of 
any element capable of chemical combination with other 
elements ? 

11. If the atomic weight of chlorine is 35.5, what is its 
molecular weight, assuming that its molecules are diatomic ? 

12. What would be its molecular weight if the molecules 
are monatomic ? 

13. If the vapor-density of mercury is 200, what is its 
atomic weight, assuming that the molecule of mercury 
contains half as many atoms as are contained in the molecule 
of hydrogen? 

14. What is Avogadro's law ? 

15. Is the smallest individual particle of any kind of 
matter capable of independent existence necessarily the 
molecule ? 

16. If the vapor-density of any given gas is twice as great 
at 500° as at 1000°, what does that difference indicate ? 

17. If a certain gas when heated to 2000° doubles in 
volume, how do you explain that expansion ? 



64 A CORRESPONDENCE COURSE IN PHARMACY 

18. Can any gas be increased in volume by an increase of 
temperature without a division of its molecules ? If so, what 
rate of expansion is possible ? 

19. State the proposition of Gay-Lussac. 

20. If you cause 3 liters of oxygen to enter into chemical 
combination with 6 liters of hydrogen, what will be the 
compound formed, and how many liters will you obtain of 
the compound in the" state of vapor ? Why ? 

21. State the law of Dulong and Petit. 

22. Define specific heat. 

23. If you divide the atomic weight of an element by 6.4, 
what is the relation of the quotient to the specific heat of 
that element ? 

24. How can the molecular weight of any substance be 
verified by its specific heat ? 

25. How can the molecular weight of any substance be 
verified by its vapor-density ? 



LESSON SIX 

To the Student: 

In this lesson, particularly in the Test Questions, you will find 
compounds named by abbreviated formulas as a more convenient 
method than by the full name. From the table of elements given in 
Lesson Five you learned the symbols of the separate elements. The 
symbol alone is supposed to represent one atom; thus, H indicates 
one atom of hydrogen; O, one atom of oxygen. If a small Arabic 
numeral is placed at the right and a little below this letter, it indi- 
cates the number of atoms; as, H 2 means two atoms of hydrogen; 
2 , two atoms of oxygen. Water is composed of two atoms of hydro- 
gen and one atom of oxygen, so the formula H 2 names water and 
indicates also its molecular composition. H 2 S0 4 means two atoms 
of hydrogen combined with one of sulphur and four of oxygen. The 
compound is sulphuric acid. Bearing these facts in mind, you will 
have no difficulty in understanding the formulas used in this lesson. 
A fuller explanation will be made to you later. 



VIII 

Chemical Polarity 

147. Positive and Negative Elements. Metals and hydrogen 
resemble each other in their chemical behavior. They can 
take each other's places in many kinds of molecules without 
radical changes of their general character and structure. 

No truly metallic element forms any truly chemical com- 
pound by direct union with hydrogen. 

All truly non-metallic elements do form chemical com- 
pounds with hydrogen. 

Water is a compound of hydrogen and oxygen. Hydrogen 
and oxygen are essentially chemical opposites. 

The most decidedly typical metals, chemically considered, 

65 



66 A CORRESPONDENCE COURSE IN PHARMACY 

are the alkali metals — caesium, rubidium, potassium, sodium 
and lithium. These metals take the oxygen away from 
water. 

The most decidedly typical non-metallic elements are 
fluorine, chlorine, bromine and iodine. These take the 
hydrogen away from water. 

When water is decomposed by an electric current, the 
hydrogen collects at the negative pole of the battery and the 
oxygen at the positive pole. Hence, as opposites attract 
each other while likes repel each other, hydrogen is called a 
positive element and oxygen a negative element. 

When a metallic compound is decomposed in a solution, 
the electric current causes the metal to be collected at the 
negative pole and the non-metallic element (or the group of 
non-metallic elements with which the metal was in chemical 
combination) is collected at the positive pole. 

Hence, all true metals are called positive elements, and the 
non-metallic elements are negative elements as compared 
with hydrogen and the metals. 

But while the metals and hydrogen are invariably positive 
in relation to all other elements, and while oxygen and 
fluorine are invariably negative in relation to all other ele- 
ments, the elements boron, carbon, silicon, nitrogen, 
phosphorus, arsenic, antimony, sulphur, selenium, tellurium, 
chlorine, bromine and iodine are negative toward the metals 
and hydrogen, but positive toward oxygen and fluorine. 

148. Chemical Polarity. By this term is meant the opposite 
qualities of elements entering into direct combination with 
each other. No two elements enter into direct combination 
unless they are of opposite qualities with respect to each other. 
Only a positive element can enter into direct combination 
with a negative element, and vice versa. 

149. Fluorine, chlorine, bromine and iodine have a greater 
affinity for hydrogen than for oxygen. In fact, fluorine 



CHEMICAL POLARITY 67 

does not enter into combination with oxygen at all, and the 
other three elements named have but a feeble inclination to 
combine with oxygen to form certain compounds called 
salts, in which they are directly united to oxygen, which 
links them indirectly to positive elements, and these salts, 
called chlorates, bromates, iodates, perchlorates, periodates, 
hypochlorites and hypobromites, are all comparatively 
unstable compounds. Chlorine and iodine are the only two 
of these four elements that form any oxides. 

150. In III, par. 106, it was stated that certain compounds 
in solution in water undergo dissociation or are split up into 
two ions, the positive ion or kation and the negative ion or 
anion. This kind of decomposition or dissociation is called 
electrolysis, and the compounds capable of electrolysis are 
called electrolytes. 

The positive electrode of an electrical battery is called the 
anode and the negative electrode is called the katode. 

When an electrolyte in solution is dissociated into its two 
ions and a galvanic current is passed through the solution, 
the positive ion or kation is collected at the katode and the 
negative ion or anion is collected at the anode. 

Water cannot be decomposed by the galvanic current 
except after adding to it some substance to act as a con- 
ductor. Sulphuric acid is used for that purpose. The 
water can then be decomposed by the electric current, with 
the result that the hydrogen of the water is invariably 
collected at the negative pole and the oxygen at the positive 
pole. 

When the chloride of any metal or of hydrogen is 
dissociated, the metal or the hydrogen is the positive ion and 
the chlorine is the negative ion. 

When potassium chloride, composed of potassium and 
chlorine, is dissociated, the potassium constitutes the posi- 
tive ion and the chlorine constitutes the negative ion. 



68 A CORRESPONDENCE COURSE IN PHARMACY 

When potassium chlorate, composed of potassium, oxygen 
and chlorine, is dissociated, potassium again alone constitutes 
the positive ion, but the oxygen and chlorine together con- 
stitute the compound negative ion. 

151. Omitting the elements that do not form any chemical 
compounds (neon, argon, krypton and xenon), and omitting 
all invariably positive elements (hydrogen and the metals), 
and the two invariably negative elements (oxygen and 
fluorine), we find that thirteen non-metallic elements re- 
main which are capable of exercising either positive or 
negative polarity, or both concurrently. A part of the 
valence of an atom of carbon, or of nitrogen, or of phos- 
phorus, or of sulphur, may be negative and the remainder 
positive. 

Whenever any one of the thirteen elements, chlorine, 
bromine, iodine, sulphur, selenium, tellurium, nitrogen, 
phosphorus, arsenic, antimony, carbon, silicon and boron, is 
in direct combination, with hydrogen or with a metal it must 
be negative ; it is positive whenever it is in combination with 
oxygen or fluorine. 

Whenever any two of the thirteen elements named are in 
combination with each other, then the one named first in 
the list is negative toward the one named after it. This 
order is determined by the relative positions of the elements 
in the periodic system or, in other words, by their respective 
atomic weights and valences. 

Thus, chlorine is negative toward all the other twelve, so 
that every binary compound* of chlorine is a chloride except 
its compounds with fluorine or with oxygen, and as the 
combining value of the negative element in any of its binary 
compounds is invariably the same, the combining value of 
the chlorine in every chloride is 1. 

* A " binary compound " is composed of but two .elements. 



CHEMICAL POLAEITY 69 

Bromine is negative toward any one of the eleven elements 
named after it, but positive toward chlorine, fluorine and 
oxygen. Hence, every binary compound of bromine must 
be a bromide except its compounds with chlorine or fluorine.* 
Fluorides and chlorides of bromine can never contain more 
than one bromine atom, because negative chlorine and 
fluorine always have the combining value of 1. 

Iodine is positive toward chlorine and bromine, but 
negative toward the other ten elements capable of varying 
polarity. Iodine has a combining value of 1 whenever it is 
in combination with any one of those ten, but no fluoride, 
chloride or bromide of iodine can contain more than one 
iodine atom, while it may contain one or three or five or seven 
atoms of F, CI or Br. 

Sulphur is positive toward chlorine, bromine and iodine, 
but negative toward the other nine; nitrogen is positive 
toward the halogens and the elements of the sulphur family, 
but is negative toward carbon ; etc. 

All the thirteen are negative toward hydrogen and the 
metals, but positive toward oxygen and fluorine. 

Whenever any one of these thirteen elements capable of 
varying polarity is directly combined with two or more other 
elements its polarity is still determined by the same natural 
law. Thus, if nitrogen is in direct combination with both 
hydrogen and oxygen, as in the compound represented by 
H 4 NOH, in which the nitrogen atom, N, holds four hydro- 
gen atoms and is at the same time in combination with the 
oxygen atom, 0, the nitrogen atom is relatively negative 
toward the hydrogen, which is positive, but relatively positive 
toward the oxygen, which is negative. In the molecule 
H 3 CC1 the carbon atom, C, is negative to the hydrogen but 
positive to the chlorine. 

* No binary compound of bromine with oxygen is known. 



70 A CORRESPONDENCE COURSE IN PHARMACY 

Test Questions 

1. Which is the positive element and which the negative 
element in a compound consisting of boron and hydrogen ? 

2. Which is the positive element and which the negative 
element in a compound of copper and arsenic ? of sulphur 
and oxygen ? nitrogen and iodine ? phosphorus and sulphur ? 
chlorine and bromine ? sulphur and carbon ? nitrogen and 
hydrogen? nitrogen and oxygen? antimony and chlorine? 
antimony and hydrogen ? 

3. Which is the positive and which the negative ion of 
potassium iodide? 

4. What is electrolysis ? 

5. What is the difference between the kation and the 
anion ? between the katode and the anode ? 

6. Name the kation of sodium nitrate (NaN0 3 ) ; the anion 
of potassium nitrate (KN0 3 ). 

7. What is the kation of sulphuric acid (H 2 S0 4 )? 

8. What is the positive ion of any acid ? 

9. Can any element in chemical combination be partly 
positive and partly negative ? 

10. Can any element be positive in some of its com- 
binations and negative in other combinations ? 

11. How can you identify the chemical polarity of any 
atom in combination ? 

12. Name the chemical polarity of each of the atoms in 
NaOCl. 

13. Which of the following molecular formulas are 
possible and which are evidently fictitious: IF 5 , FC1 3 , 
BrF, BrF 5 , ClBr 5 , C1F 5 , IBr 7 , Brl 7 ? 

14. Identify the positive and negative elements in the 
compound represented by H 4 NC1 and in H 4 NON0 2 . 



LESSON SEVEN 
IX 

Binary Compounds 

152. A binary compound is a molecule composed of but 
two elements — one positive and the other negative — united 
to each other in such a way that each atom of one is held in 
direct combination with each atom of the other. 

The most simple chemical compound possible is a binary 
compound consisting of but two atoms, one atom of each 
element. As examples of such compounds we may mention 
sodium chloride, represented by the molecular formula NaCl ; 
lime or calcium oxide, represented by OaO ; and hydrogen 
chloride, HC1. 

Other binary compounds contain one atom of one element 
and two of the other; as, for example, water, H 2 0, and 
calcium chloride, CaCl 2 . 

Other binary compounds contain one atom of one element 
united to three or four or five or six atoms of the other ; or 
two atoms of one united to two, three, five or seven atoms of 
the other. 

But no compound consisting of two elements is truly a 
binary compound if it contains two or more atoms of one and 
the same kind directly united to each other. Thus, any 
compound containing two or more oxygen atoms held to 
each other, or two or more atoms of carbon directly joined 
to each other, or two or more atoms of any one other element 
directly united together, is not a true binary compound. In 

71 



72 A CORRESPONDENCE COURSE IN PHARMACY 

the compound called hydrogen dioxide there are two hydrogen 
atoms and two oxygen atoms ; the two atoms of oxygen are 
assumed to be united to each other, and of the two hydrogen 
atoms one is united to each oxygen atom so that the arrange- 
ment of the four atoms may be represented by a chain, thus : 
HO OH. Hence H 2 2 is not a true binary compound, 
although it contains but two elements. But aluminum 
oxide, A1 2 3 , is a true binary compound, because its two 
atoms of aluminum are both held to be directly united to all 
the three oxygen atoms which it contains, as represented by 
the following structural formula : 

Al— 0— Al 

\o/ 

153. The names of binary compounds are derived from 
their negative elements and they are given the ending 
" — ide." Thus a binary compound of oxygen is called an 
oxide ; all binary compounds of fluorine are called fluorides ; 
all binary compounds of chlorine are called chlorides, except 
the oxides of chlorine (and the fluorides if any exist) ; all the 
binary compounds of bromine are called bromides, except its 
compounds with chlorine and fluorine;* iodides are the 
binary compounds formed by iodine with all elements except 
bromine, chlorine, fluorine and oxygen. All binary com- 
pounds of the metals are named after their non-metallic 
elements, because the metals are invariably positive and any 
element in direct combination with a metal is consequently 
negative in such a compound and must be a non-metallic 
element. 

154. The truly binary compounds, then, are of fifteen 
classes (and only fifteen), according to their negative ele- 
ments, namely: 

* Bromine does not form any known binary compound with oxygen. 



BINARY COMPOUNDS 



73 



Fluorides, containing fluorine. 
Oxides, containing oxygen. 



Chlorides, containing negative chlorine. - 


Bromides, 


bromine. 


Iodides, " ' 


iodine. 


Sulphides, 


' sulphur. 


Selenides, " ' 


selenium. 


Tellurides, 


tellurium. 


Nitrides, " ' 


nitrogen. 


Phosphides, 


phosphorus 


Arsenides, " 


arsenic. 


Antimonides, 


antimony. 


Carbides, " 


carbon. 


Silicides, 


silicon. 


Borides, " ' 


boron. 



No other binary compounds are known. 

155. True binary compounds containing fluorine, chlorine, 
bromine or iodine are called Halides. They never contain more 
than one atom of the element united to the negative halogen. 

Compounds such as S 2 I 2 (consisting of two atoms of 
sulphur and two of iodine) and Fe 2 Cl 6 (composed of two 
atoms of iron and six of chlorine) exist, but they are not 
true binary compounds. In S 2 I 2 the sulphur atoms are 
united directly to each other as well as to the iodine (see 
par. 152). The compound Fe 2 Cl 6 is a " double molecule" or 
a combination of FeCl 3 with FeCl 3 , and it is not understood 
how these two molecules of FeCl 3 are held to each other 
(unless the iron atoms are tetrads and directly united to 
each other. The position of iron in the periodic system 
favors this view). 

156. The fluorides, chlorides, bromides and iodides of the 
metals are all solids at ordinary temperatures. Those of the 
non-metallic elements are either solids, liquids or gases. 

157. Sulphides are formed by nearly all elements except 
oxygen, fluorine, chlorine, bromine, iodine, neon, argon, 
krypton, and xenon. 



74 A CORRESPONDENCE COURSE IK PHARMACY 

The sulphides of metals are solids, and those formed by 
the heavy metals are all insoluble in water. 

The nitride of hydrogen is commonly called ammonia and 
is composed of three hydrogen atoms and one nitrogen atom, 
so that the molecule is represented by the formula H 3 N". 

The phosphide of hydrogen is called phosphine and is 
H 3 P. There is also an arsenide of hydrogen, H 3 As, called 
arsine, and a hydrogen antimonide, H 3 Sb, called stiline. 
All of these hydrogen compounds are gaseous. 

Saturated hydrogen carbide containing but one carbon 
atom is called "marsh gas," or methane, and has the molec^- 
ular formula H 4 C, the carbon atom holding four hydrogen 
atoms in combination with itself. 

Hydrogen silicide is H 4 Si, and hydrogen boride is H 3 B. 

158. From this chapter the student will perceive that 
binary compounds have a comparatively simple structure. 

No true binary compound can have molecules containing 
more than nine atoms, as in Mn 2 7 . 



The Hydroxides, Acids, Bases and Salts 

159. The Hydroxides. One atom of hydrogen and one of 
oxygen united to each other form an atomic group called 
hydroxyl. This group cannot exist alone, but it forms 
numerous compounds. The compounds which single ele- 
ments form with hydroxyl are called hydroxides. 

The symbol for an atom of hydrogen being H and that for 
the oxygen atom 0, the formula representing the radical 
called hydroxyl is HO or OH. 

The most common of all hydroxides is water, for the 
formula HOH is more significant of the true character of 



THE HYDKOXIDES, ACIDS, BASES AND SALTS 75 

the compound than H 2 0. Water is the oxide of hydrogen, 
but it is also the hydroxide of hydrogen. It is the only 
compound which is at once both an oxide and a hydroxide. 

All true acids contain hydroxyl, and several other im- 
portant; classes of compounds also contain the group OH. 

160. Acids. Vinegar is acid or sour because it contains 
acetic acid. Lemon juice is sour from citric acid. Sour 
milk owes its sour taste to lactic acid. Pie plant contains 
oxalic acid. All acid or acidulous fruits contain some 
organic acid or some compound formed by it. Sour grapes 
are tart because they contain a compound called acid tartrate 
of potassium, which is formed by tartaric acid and which in 
its purified state is called cream of tartar, the sour taste of 
which is familiar. 

Acetic acid, citric acid, lactic acid, oxalic acid and tartaric 
acid are all organic acids, because they are acids contained 
in or obtained from organic substances, or substances belong- 
ing to the vegetable and animal worlds. 

But several inorganic acids having an even more decidedly 
sour or acid taste are common. Among them are sulphuric 
acid, nitric acid, hydrochloric acid and phosphoric acid. 
The commercial impure strong sulphuric acid was formerly 
called oil of vitriol; nitric acid was known as aqua fortis, 
and impure strong hydrochloric acid was called muriatic 
acid. These names are still used by persons to whom the 
scientific names are not known. These strong acids are 
corrosive or destructive in their effects upon numerous other 
substances, including nearly all vegetable and animal matter. 
They are therefore poisonous and dangerous and must be 
handled with great caution. They should never be tasted 
except after dilution with at least ten times their weight of 
water, and even after that dilution they are still destructive. 
Many of the metals dissolve in the strong acids. 

Characteristic and strong acids, if water-soluble, have an 



76 A CORRESPONDENCE COURSE IN" PHARMACY 

acid or sour taste, and even after great dilution with water 
they change the color of blue litmus to red. They lose these 
properties, partially or entirely, when brought into contact 
with bases, forming salts- which are not destructive in their 
effects upon other substances. 

But not all acids have an acid taste, or corrosive properties, 
nor do all acids turn blue litmus red. Many acids are 
insoluble in water and have no taste; others are but feebly 
acidulous, and affect litmus but slightly. But all acids, 
however feeble, have the power to overcome the corrosive 
properties of the strongest alkalies and to form salts. Any 
substance is an acid if its composition and structure are 
analogous to those of the sour acids mentioned, and if it 
forms a salt with any alkali. 

Some acids are liquids; others are solids, and still other 
acids are gaseous. 

All acids contain hydrogen. If in any hydrogen com- 
pound all or a part of the hydrogen can be replaced by any 
metal with the result that a salt is thereby produced, that 
hydrogen compound is an acid. 

161. Four kinds of so-called acids, and only four, are each 
composed of only two elements, one of which is hydrogen. 
They are: hydrofluoric acid, composed of hydrogen and 
fluorine; hydrochloric acid, composed of hydrogen and 
chlorine; hydrobromic acid, composed of hydrogen and 
bromine; and hydro-iodic or hydriodic acid, composed of 
hydrogen and iodine. They are called hydrogen acids, or 
hydracids. But the structure of those compounds differs 
radically from that of the hydroxyl acids, which contain 
oxygen as well as hydrogen, and distinction must in any 
scientific classification be made between the hydrogen acids, 
which are binary compounds, being the halides of hydrogen, 
and the hydroxyl acids, which contain more than two 
elements. 



THE HYDROXIDES, ACIDS, BASES AND SALTS 77 

The true scientific names of the so-called hydrogen acids 
are hydrogen fluoride, hydrogen chloride, hydrogen bromide 
and hydrogen iodide. 

162. Hydroxyl acids are the acids formed by the chemical 
elements with hydroxyl, or with hydroxyl and oxygen, or 
with hydroxyl hydrogen and oxygen. All the true inorganic 
acids are hydroxyl acids. They are also frequently called 
"oxygen acids." 

Boric acid is composed exclusively of boron and hydroxyl 
and its molecular formula is B(OH) 3 , because it contains one 
boron atom united to three groups of OH. Sulphuric acid 
is written (HO) 2 S0 2 , because it is composed of one sulphur 
atom, two groups of OH and two additional oxygen atoms. 
Hypophosphorous acid is written HOPH 2 0, because it is 
composed of one phosphorus atom, one group of hydroxyl, 
two hydrogen atoms, and one oxygen atom. 

The organic acids contain the group CO, called carbonyl, 
as well as the hydroxyl group, or they are described as con- 
taining CO OH, which is called carloxyl. 

163. Alkalies. "Caustic potash," "caustic soda" and 
"ammonia" are the principal alkalies. Potash and soda are 
white solids. Ammonia is the gaseous hydrogen nitride, 
but a water solution of it, commonly called "ammonia" or 
"water of ammonia," is familiar to most persons. 

A solution of caustic potash in water is called "potash- 
lye," and a solution of caustic soda is "soda-lye." Strong 
potash-lye and soda-lye are so corrosive and destructive that 
they "eat into" wood, dissolve flesh, and disintegrate bone. 
Strong ammonia solutions also attack organic matter in a 
destructive way. 

These alkalies have a burning, caustic, alkaline, lye-like 
taste; but their destructive character is such that they 
should not be tasted except after very great dilution with 
water. 



78 A CORRESPONDENCE COURSE IN PHARMACY 

Strong alkalies, being so destructive, and, therefore, also 
poisonous, must be handled with great caution. 

Even after large dilution the solutions of alkalies change 
the color of red litmus to blue. 

164. Opposite Properties of Acids and Alkalies. While the 
strong acids and the strong alkalies are alike destructive in 
their effects upon animal and vegetable tissues, they are 
chemically opposites, for, when an acid and an alkali are 
mixed together in certain definite proportions, the corrosive 
or. destructive properties of each are entirely removed or 
neutralized, the power of the acid to turn blue litmus red 
and that of the alkali to turn red litmus blue is taken 
away, and the sour taste of a strong acid is overcome by 
the alkali and the alkaline taste of the alkali is overcome 
by the acid, the product of the two having a taste 
altogether different from that of either acid or alkali. 

When acids and alkalies mutually neutralize or saturate 
each other they form a new compound called a salt. But 
the corrosive or destructive action and other properties of a 
strong acid are never diminished by the addition of another 
acid, nor are the characteristic properties of a strong alkali 
changed or diminished by the addition of another alkali or 
a base. 

165. Experiments to Prove the Opposite Properties of Acids 
and Alkalies. Take a small quantity of vinegar, which is 
diluted acetic acid, or of any ^ther diluted acid, and dip a 
strip of blue litmus paper in it ; it will turn the paper red. 
Taste the diluted acid and note its sour taste. 

Dip a strip of red litmus paper in some diluted ammonia 
water; it will turn the paper blue. Taste the diluted 
ammonia and note its lye-like taste. 

Add ammonia water gradually to a little of the vinegar 
and test the mixture repeatedly with blue litmus paper. 
Observe that the power of the vinegar to turn the blue litmus 



THE HYDROXIDES, ACIDS, BASES AND SALTS 79 

paper red is gradually lessened as more ammonia is added, 
and that finally, when enough ammonia has been used, the 
mixture does not change the color of the blue litmus paper 
at all. When this point has been reached the liquid has no 
longer a sour taste. If the quantity of ammonia added is 
just sufficient to neutralize the acetic acid, the liquid will 
neither turn blue litmus paper red nor red litmus paper blue, 
and the taste of the mixture will be neither that of vinegar 
nor that of ammonia, but a saline taste which is altogether 
different. If an excess of ammonia is added the liquid will 
then turn red litmus blue and its taste will be that of the 
ammonia. 

If the order of mixing be reversed, the vinegar being 
gradually added to the ammonia, then the power of the 
ammonia to turn red litmus paper blue will be gradually 
weakened and will be completely overcome as soon as enough 
vinegar has been added; and if more vinegar is added the 
liquid will acquire the power to turn blue litmus red and 
will then have an acidulous or acid taste, imparted by the 
excess of acetic acid. 

Like results will be obtained whatever may be the kind of 
acid used or the kind of alkali or base. 

As alkali carbonates also have the property of neutralizing 
acids, the experiment may be made with baking soda or 
sodium bicarbonate instead of ammonia. 

166. Bases. By a base is meant, in inorganic chemistry, 
any hydroxide (or any oxide) having the power to neutralize 
acids and form salts by reaction with them. 

The alkalies are accordingly bases, for they are hydroxides 
capable of neutralizing acids and forming salts with them. 
The alkalies are in fact the strongest bases known. 

But very few bases have decidedly alkaline properties. 

Only the water-soluble metallic hydroxides and ammonia 
solutions are called alkalies. 



80 A CORRESPONDENCE COURSE IN PHARMACY 

Most of the inorganic bases are not only insoluble in water, 
but on that account tasteless and apparently chemically inert 
in their behavior toward other substances, except the acids 
and some of the non-metallic elements. Insoluble metallic 
oxides and hydroxides do not change the color of litmus at 
all ; but they have the power wholly or partly to neutralize 
acids, and to form salts with them. 

The great majority of bases are solids; but some are liquid 
and others gaseous. The metallic bases are all solids. 

187. Basic Properties and Functions. The most impor- 
tant characteristic property of bases is their power to form 
salts with the acids. "This property or function is in any 
metallic base due to the metal or basic element in it. All 
metals having oxides or hydroxides which exhibit basic 
properties are said to have the power to exercise the basic 
function. In fact, any metal which forms any salt with any 
acid exercises a basic function in the formation of that salt, 
whether any oxide or hydroxide of that metal exists or not. 

168. Acidic Properties and Functions. The property of 
acids to form salts with the bases, or to exchange their 
hydrogen, or a part of it, for a metal, thereby forming salts$ 
is their most important characteristic. It is due to the 
acidic element or acidic atomic group contained in the acid. 

The true inorganic acids are compounds formed by an 
acidic element with hydrogen and oxygen. The acidic ele- 
ment of the most strikingly characteristic acids is a non- 
metallic element. In fact, all non-metallic hydroxides are 
acids. But several of the metals also have the power to 
form acids or to exercise the acidic function under certain 
conditions. 

Sulphuric acid is composed of hydrogen, oxygen and 
sulphur; the sulphur is the acidic element and performs the 
acidic function in that acid. Nitrogen is the acidic element 
of nitric acid, which is composed of hydrogen, oxygen and 



THE HYDROXIDES, ACIDS, BASES AND SALTS 81 

nitrogen. Carbon is the acidic element in carbonic acid; 
phosphorus in phosphoric acid ; chromium in chromic acid ; 
chlorine in chloric acid; arsenic in arsenous acid; etc. 

169. Salts are chemical compounds formed by the acids 
with the bases. 

As the inorganic bases are either oxides or hydroxides of 
the metals, it follows that the inorganic salts are all metallic 
cpmpounds or contain metals in chemical combination. 

The metallic salts formed by the inorganic acids, therefore, 
generally contain three elements — the basic element, the 
acidic element and oxygen. 

In the salt called potassium nitrate the basic element is 
potassium, the acidic element is nitrogen, and the third 
element is the oxygen; the formula is commonly written 
KN0 3 , because it contains one atom of each of potassium and 
nitrogen, but three atoms of oxygen. In sulphate of copper 
the basic element is copper, the acidic element sulphur, and 
the common formula is CuSO^. In permanganate of potas- 
sium the basic element is potassium, and the acidic element 
manganese; the common molecular formula is KMn0 4 . 

But a salt may contain more than one basic element, as in 
A1K(S0 4 ) 2 ; or hydrogen as well as metals, as in Na 2 HP0 4 ; 
or hydrogen united directly to the acidic element, as in 
NaPH 2 2 . 

The difference between the composition of a hydroxyl acid 
and a metallic salt formed by such an acid is that the acid 
contains hydrogen instead of the metal and the salt contains 
metal instead of the hydrogen or part of it. The compo- 
sition of sulphuric acid is expressed by the common formula 
H 2 S0 4 , and the composition of its potassium salt, called 
potassium sulphate, is expressed by the formula K 2 S0 4 . 

The acids may, therefore, be consistently regarded as the 
salts of hydrogen, with hydrogen performing the basic 
function. 



82 A CORRESPONDENCE COURSE IN PHARMACY 

170. Halides. The compounds formed by the action of 
"hydrogen acids" upon the bases are called halides. Their 
structure is radically different from that of the true salts or 
oxygen salts described in the preceding paragraph, formed 
by the true acids or hydroxyl acids, for the metallic halides 
contain only two elements, one of which is either fluorine, 
chlorine, bromine or iodine, while the other is a metal. The 
halides are scientifically called the fluorides, chlorides, bro- 
mides and iodides of the metals. 

As to structure, the halides formed by the metals are 
perfectly analogous to the fluorides, chlorides, bromides and 
iodides of the non-metallic elements. The structure of tri- 
chloride of phosphorus is represented by P01 3 and that of 
chloride of aluminum by A1C1 3 . 

171. Scientific classification and nomenclature are neces- 
sary to a clear understanding of the composition and structure 
of matter. Many of the common names applied to chemical 
compounds are unfortunately unscientific, inconsistent, or 
misleading. 

Solid substances made by early chemists were commonly 
called salts if they resembled sodium chloride in outward 
form and appearance, and especially if they were soluble in 
water. But many substances that look like salts are not 
salts at all, as, for instance, boric acid, oxalic acid, ice, snow, 
rock candy, and numerous other common kinds of matter. 
On the other hand, glass, olive oil, chalk, marble, limestone, 
clay, soap, oil of wintergreen and butter, none of which bear 
any outward resemblance to our common salt or sodium 
chloride, are really all of them salts, for they have 
the chemical structure of salts, and are formed by acids 
with bases. Sodium chloride is not a true salt, because 
it does not have the structure of a salt, but is a simple 
binary compound, whereas all true salts contain at least 
three elements. 



THE HYDKOXIDES, ACIDS, BASES AND SALTS 83 

172. The names of salts are derived from the names of the 
acids by which they are formed. Thus all salts formed by 
nitric acid are called nitrates; those formed by sulphuric 
acid are called sulphates; those of phosphoric acid are 
phosphates; acetic acid forms acetates; carbonic acid, 
carbonates; oxalic acid, oxalates; citric acid, citrates; 
tartaric acid, tartrates ; and chloric acid, chlorates. Nitrous 
acid forms nitrites; sulphites are the salts of sulphurous 
acid ; and the salts of arsenous acid are called arsenites. 

173. As the salts are generally produced out of the acids 
and bases, so the salts can be decomposed again and the 
acids and bases of which they were made reproduced, or 
one salt may be transformed into another salt by chemical 
means. Nitric acid can be made from nitrates, sulphuric 
acid from sulphates, acetic acid from acetates, nitrous acid 
from nitrites, etc. 

174. Some Familiar Salts. Saltpeter is potassium nitrate, 
or the potassium salt of nitric acid, and is composed of 
potassium, nitrogen and oxygen. 

Washing soda is sodium carbonate, or the sodium salt of 
carbonic acid, and is composed of sodium, carbon and oxygen. 

Baking soda is another sodium salt of carbonic acid. It is 
called "bicarbonate of sodium" or ' ' acid carbonate of sodium, ' ' 
because in this sodium carbonate there is but one sodium atom, 
while in the other there are two, so that the quantity of the group 
C0 3 in proportion to sodium is twice as great in the bicarbonate. 
The composition of sodium carbonate is commonly repre- 
sented by Na 2 C0 3 ; that of the bicarbonate by NaHC0 3 . 

Epsom salt is magnesium sulphate, or the magnesium salt of 
sulphuric acid, composed of magnesium, sulphur and oxygen. 

Green vitriol is one of the iron salts of sulphuric acid, or, 
in other words, a sulphate of iron. 

White vitriol is zinc sulphate, and blue vitriol is copper 
sulphate. 



84 A CORRESPONDENCE COURSE IN PHARMACY 

True alum is a double sulphate ; it has two basic elements, 
namely aluminum and potassium. 

Limestone, chalk and marble are all different forms of 
calcium carbonate. 

175. An elementary lesson in the chemistry of limestone 
will serve to show the relations of oxides, hydroxides, acids, 
bases and salts to one another. 

When calcium carbonate (limestone) is strongly heated 
or "calcined" in a limekiln it is decomposed into calcium 
oxide or "lime" and carbon dioxide, which is a colorless gas. 
Lime or calcium oxide is caustic and destructive to animal 
and vegetable tissues. It is a powerful basic oxide. 

When water is added to lime the two substances act upon 
each other chemically and calcium hydroxide is formed. 
This is strongly alkaline, and turns red litmus blue. 

When carbon dioxide is collected in water it forms carbonic 
acid with the water, and carbonic acid turns blue litmus 
paper red. 

Now if either the calcium oxide ("quick lime") or the 
calcium hydroxide ("slaked lime") be exposed to the action 
of the carbon dioxide ("carbonic acid gas") or to the carbonic 
acid solution, we will get calcium carbonate back again. 
This does not change the color of either blue or red litmus 
paper. 

But although calcium oxide and water may be said to 
unite to form calcium hydroxide, and although this calcium 
hydroxide when strongly heated splits up again into 
calcium oxide and water, there is in reality neither water 
nor calcium oxide in the calcium hydroxide. 

And although carbon dioxide and water form carbonic 
acid together, and although carbonic acid may be easily split 
up so as to form water and carbon dioxide, carbonic acid is 
not composed of water and carbon dioxide. 

To the beginner in chemistry these statements doubtless 



THE HYDKOXIDES, ACIDS, BASES AND SALTS 85 

must appear paradoxical ; but there will be no difficulty in 
understanding them by the aid of symbolic formulas. 

Water is composed of two hydrogen atoms and one oxygen 
atom, the two hydrogen atoms being both of them united 
directly to the oxygen atom, so that the molecular formula is 
best represented as HOH. But there is no HOH in either 
carbonic acid or in calcium hydroxide. 

If calcium be represented by Oa, hydrogen by H, oxygen 
by 0, and carbon by 0, then the relative positions of the 
several atoms composing calcium oxide, water, calcium 
hydroxide, carbon dioxide and carbonic acid, respectively, 
may be pictured as follows : 

CaO HOH HOCaOH 

Calcium Oxide. Water. Calcium Hydroxide. 


000 HOH HOOOH 

Carbon Dioxide. Water. Carbonic Acid. 

If sulphuric acid be added to calcium carbonate we get 
calcium sulphate water and carbon dioxide: 

Ca<3£>C=0 + (HO) 2 S0 2 = Ca0 2 S0 2 + 
Calcium Carbonate. Sulphuric Acid. Calcium Sulphate. 
HOH + OCO 
Water. Carbon Dioxide. 

Test Questions 

1. Which of the following formulas represent binary com- 
pounds and which of them do not represent such compounds : 
Fe 2 3 , Fe(OH) 3 , H 2 S 2 , Ag 2 0? 

2. What name would you give a binary compound contain- 
ing tellurium ? 

3. What is the negative element in a phosphide ? What 
is the positive element in an arsenide ? 

4. To what class of compounds would you refer a substance 



86 A CORRESPONDENCE COURSE IN PHARMACY 

composed of copper and sulphur ? To what, a substance com- 
posed of copper and zinc ? 

5. What kind of a compound is KOH ? Mn0 2 ? 

6. What is HO? H 2 ? H 2 2 ? 

7. What is your understanding of what constitutes an acid ? 

8. What is the true scientific name of hydrobromic acid ? 

9. What elements are contained in all true acids, as well 
as in all alkalies ? Mention six acids ; three alkalies. 

10. What is the difference between a base and an alkali ? 

11. What elements can exercise basic functions? Can 
any metals exhibit acidic properties ? 

12. What is the basic element of caustic soda ? of caustic 
potash ? 

13. What is the acidic element of boric acid ? of carbonic 
acid ? of chloric acid ? of iodic acid ? of antimonic acid ? of 
permanganic acid ? What is a salt ? 

14. What is the common name of hydrogen borate ? 

15. What is the difference between hydrogen chlorate and 
potassium chlorate ? 

16. What is a halide ? a phosphite ? a phosphate ? a 
sulphite ? a sulphate ? an arsenite ? 

17. What is baking soda, chemically considered ? What 
is the difference between baking soda and washing soda ? 

18. What is the difference between green vitriol, blue 
vitriol and white vitriol ? 

19. Mention three common forms of calcium carbonate. 

20. What is the difference between lime and limestone ? 
between lime and slaked lime ? between carbon dioxide and 
carbonic acid ? between carbonic acid and chalk ? 

21. What is the difference between water and calcium 
hydroxide ? 



LESSON EIGHT 
XI 

Atomic Valence 

176. The number of atoms of any one kind which can be 
held in combination by any given number of atoms of any 
other kind is subject to natural law. Thus, for example, 
the number of hydrogen atoms which can be held in direct 
chemical combination by a single atom of any one other 
element in a binary compound is a constant number. One 
atom of either fluorine, chlorine, bromine or iodine can hold 
in combination with itself only one hydrogen atom; one 
atom of either oxygen, sulphur, selenium or tellurium can 
hold neither more nor less than two hydrogen atoms in 
combination with itself; a single atom of nitrogen, phos- 
phorus, arsenic, antimony or boron can hold in combination 
with itself neither more nor less than three hydrogen atoms ; 
and neither more nor less than four hydrogen atoms can be 
held in direct combination by a single atom of either carbon 
or silicon to form a binary compound. 

No one single individual atom of any kind can hold in direct 
combination with itself more than four hydrogen atoms. 

The individual combining value of one single atom of 
any given element as compared with the combining value of 
one single atom of any other given element is called its 
valence. It is also called the combining power, or combining 
value, or saturating capacity, or saturation value, or valency, 
or quantivalence of the element. 

87 



88 CORRESPONDENCE COURSE IN PHARMACY 

177. The hydrogen valence of an element is the number of 
hydrogen atoms which a single atom of the element can hold 
in direct combination with itself, when united by all of its 
combining power directly or exclusively to hydrogen. 

Prom the preceding paragraphs it will be seen that the 
hydrogen valence of any given element is constant and that 
it may be 1, 2, 3 or 4, but can in no case exceed 4. 

178. To find the oxygen valence of any element the follow- 
ing rule is generally applicable : Divide the number of oxygen 
atoms contained in one molecule of the oxide of the element 
by one-half the number of the other atoms in the same 
molecule. 

By the application of this rule we find from K 2 that the 
oxygen valence of K is 1 ; from CaO that the oxygen valence 
of Ca is 2; from A1 2 3 that the oxygen valence of Al is 3; 
from C0 2 that the oxygen valence of the C in that compound 
is 4; from CO that the oxygen valence of the C in CO is 2. 
We find that the oxygen valence of the N in N 2 is 1, that 
it is 2 in NO, 3 in N 2 3 , and 5 in N 2 5 . 

But we cannot discover the oxygen valence of the Fe in 
the compound expressed by the formula Fe 3 4 by the 
application of the rule given, because Fe 3 4 is not a true 
binary compound, but either a combination of two molecules 
— FeO and Fe 2 3 — or it may be a salt (Fe 2 4 Fe, or Fe 2 Fe0 4 ). 

179. The valence of the hydrogen atom is invariably 1, 
because the hydrogen atom is the adopted standard of com- 
parison. Thus, the valence of any other atom is the number 
of hydrogen atoms which it equals in combining power, or 
the number of hydrogen atoms for which it can be exchanged, 
or the number of hydrogen atoms which it is capable of 
holding in combination. 

180. The valence of the oxygen atom in combination is 
invariably 2. Hence any single atom of any other element 
which holds in direct combination with itself one single atom 



ATOMIC VALENCE 



89 



of oxygen must also have a valence of 2. (Compare this 
statement with par. 178.) 

181. The following named elements have a constant 
valence : 

The valence of H, Li, Na, K, Eb, Cs, Ag and F is invaria- 
bly 1. 

The valence of Be, Mg, Ca, Sr, Ba, Zn, Cd and is 
invariably 2. 

The valence of Al and B is invariably 3. 

182. The highest possible valence attainable by any atom 
is 8. But only two elements are known to attain that 
valence, namely Os and Eu. 

Whenever any atom attains a valence exceeding 6 it is in 
combination with oxygen. 

No single atom of any element can hold in direct com- 
bination with itself more than four oxygen atoms to form a 
Unary compound. 

No single atom of any element can hold in combination 
with itself more than six chlorine atoms. 

183. Bonds. The term bond is very conveniently employed 
to express the unit of valence. 

Thus we say that the hydrogen atom, having a valence of 
1, has 1 bond. The oxygen atom has 2 bonds, because its 
valence is 2. The atom of Os has 8 bonds in the compound 
Os0 4 . Sulphurhas6bondsinS0 3 . Carbonhas4bondsinC0 2 . 

184. Atoms having an even number of bonds (2, 4, 6 or 8) 
are called artiads; atoms having an odd number of bonds (1, 
3, 5 or 7) are called perissads. 



Atoms having a valence of 1 are ca 
2 ' 
3 
4 
5 
6 
7 
8 



led monads and have 1 bond 



diads 


( a 


2 bonds 


triads 


i ti 


3 " 


tetrads 


t (i 


4 " 


pentads 


( cc 


5 " 


hexads 


c a 


6 " 


heptads 


i a 


7 " 


octads 


( u 


8 " 



90 A CORRESPONDENCE COURSE IN PHARMACY 

Monads are univalent. 
Diads are bivalent. 
Triads are trivalent. 
Tetrads are quadrivalent. 
Pentads are quinquivalent. 
Hexads are sexivalent. 
Heptads are septivalent. 
Octads are octivalent. 

185. The manner in which atoms are held in combination 
with each other in the formation of molecules may be 
represented by picturing their bonds as connecting links 
between them. Using lines to represent the bonds or units 
of valence, we may readily see that HOI is H — — OL; that 
H 2 2 mustbe represented as H — — — H; that H 3 N and 

H H 

I I 

H 4 C must be H— N— H and H— C— H; that A1 2 3 must be 



/0\ 

Al — — Al, and that C 7 H 16 may be represented as 

H H H H H H H 

I I I I I I I 
H— C— C— C— C— C— C— C— H 

I I I I I I I 
H H H H H H H 

The student must keep in mind that the term "bond" is 
used only in a figurative sense to express units of valence, 
and that atoms are not possessed of any links, or ligaments, 
arms, projections, handles, or points of attachment, by which 
they may be tied or united or held to each other. 

186. Atomic Linking. The relative positions of the atoms 
in a molecule and the way in which they are held to each 
other according to their respective valences is called the 
atomic linking of the molecule. It is of supreme importance 
as the only means at present known by which the structure 



ATOMIC VALENCE 91 

of chemical compounds may be understood and the com- 
pounds themselves scientifically classified, especially in 
organic chemistry. 

187. Variable Valence. A variable atomic combining 
value or valence is possible only to atoms exercising positive 
polarity, or, in other words, to atoms having positive bonds. 

188. All atoms of exclusively negative polarity have a 
constant valence, or a fixed valence according to their kind. 
Thus, negative fluorine, chlorine, bromine and iodine are 
invariably monads; atoms of sulphur, selenium and tellurium 
are invariably diads whenever their bonds are all negative; 
boron, nitrogen, phosphorus, arsenic and antimony atoms 
invariably have three bonds whenever all their bonds are 
negative; carbon and silicon atoms invariably have four 
bonds whenever their bonds are all of negative polarity. 
See also paragraphs 176 and 177. 

189. All bonds by which hydrogen is held in combination 
must be negative bonds, because hydrogen itself is invariably 
of positive polarity in all its compounds. 

190. All bonds by which oxygen is held in combination 
must be positive bonds, because all the bonds of oxygen itself 
are invariably of negative polarity in all its compounds. 

191. The valences of positive elements are found from the 
composition of their oxides, chlorides and salts. 

The valence of any negative element is the number of 
hydrogen atoms which one single atom of it can hold in 
combination. 

192. It is evident that any atom having but one bond can 
be in combination with only one other atom, as in KC1, HBr, 
or Agl. 

Any atom having two bonds, as, for instance, the oxygen 
atom, can hold either one other atom having the same 
number of bonds, as in CaO, or two other atoms having one 
bond each, as in HOH and KOH. 



92 A CORRESPONDENCE COURSE IN PHARMACY 

Any atom having three bonds can hold in combination 
either one other atom having three bonds, as in BN ; or one 
atom having two bonds and another having one bond, as the 
Bi in OBiCl or the N in H 2 NHgCl, or it can hold three 
atoms having one bond each, as in H 3 N or NI 3 . 

Any atom having four bonds may hold four other atoms 
having one bond each, as in H 4 C, C01 4 , H 3 0C1, H 2 CC1 2 , 
HCClg, etc. ; or it may hold one other atom having three 
bonds and one having but one bond, as the C in HON; or it 
may hold two other atoms having two bonds each, as the 
C in OCO, or C0 2 . 

Any atom having five bonds may hold one other atom with 
four bonds and one with but one bond; or it may hold five 
other atoms with, one bond each; or any number of other 
atoms having a total of five bonds. 

Other combinations possible are shown in WC1 6 , N 2 5 , 

Mn 2 7 , and in O — O, Ca/2^0 = and 



NO/ 



H 



/ \ / ^ \ 

B.— C / 0— H HC^ COH 

I II and I || 

H-C. C— H HC. CH. 

C C 

I I 

H H 

193. There can be no free or uncombined bond in any 
molecule. 

194. The total number of bonds in any molecule must be 
an even number, and one half of the whole number must 
be positive bonds and the other half negative bonds, for 



THE ALGEBRAIC COMBINING NUMBERS OP ATOMS 93 

every bond must be met by and united to another bond of 
opposite polarity. 



XII 

The Algebraic Combining Numbers of Atoms 

195. While the valence of an atom is the number of its 
bonds in actual combination, there is clearly a radical 
difference between an atom having only positive bonds 
incapable of assuming negative polarity, another atom having 
only negative bonds incapable of assuming positive polarity, 
and a third atom having both positive and negative bonds, 
even if the total number of bonds of each atom be the same. 

Metals and hydrogen can be held in combination with 
other elements only by negative bonds. Oxygen and fluorine 
can be held in combination with other elements only by 
positive bonds. Atoms having both positive and negative 
bonds can hold metals or hydrogen by their negative bonds, 
and at the same time oxygen by their positive bonds. 

To indicate such differences the positive bonds may be 
designated by the plus sign (+) and the negative bonds by 
the minus sign (— ). If we then add together algebraically 
all the bonds of any one atom in actual combination, the 
sum will express truly the real combining value of that atom. 
The writer of this book has elsewhere called this sum the 
"polarity-value" of the atom. It may also be called the 
algebraic combining number of the atom. 

196. The algebraic combining number of any atom having 
only positive bonds, or one having a greater number of 
positive than of negative bonds, is of course a plus quantity. 
The algebraic combining number of any atom having only 
negative bonds, or one having a greater number of negative 
than of positive bonds, must be a minus quantity. And the 



94 A CORRESPONDENCE COURSE IK PHARMACY 

algebraic sum of any atom having an equal number of positive 
bonds and negative bonds must be 0. 

197. By this method we will be able to see clearly that the 
range of true combining value possible to any one atom 
never exceeds 8 units. Thus the lowest algebraic combining 
number of the chlorine atom is — 1, for negative chlorine is 
always a monad ; and the highest combining number of 
chlorine, shown in KC10 4 , is +7, because the four oxygen 
atoms together have 8 negative bonds and hence the K and 
CI must together have 8 positive bonds, of which only 1 
belongs to the potassium. The same range is seen in iodine. 

The lowest algebraic combining number of sulphur is —2, 
which is its value in all sulphides ; and its highest algebraic 
combining number is -f 6, as in S0 3 . 

The lowest algebraic combining number of nitrogen, as 
shown in ammonia (H 3 N) and in all ammonium compounds, 
is -3 ; and its highest combining value, as shown in N 2 5 
and in the nitrates, is +5. 

The nitrogen has an algebraic combining number amount- 
ing to —3 in all ammonium compounds, as may be shown here 
by one example. The molecule of ammonium chloride is 
H 4 NC1; hence the nitrogen atom here has four negative 
bonds which hold the positive hydrogen atoms in combination 
and one positive bond holding the negative chlorine atom, 
and the sum of —4 and +1 is —3. 

The lowest algebraic combining value of carbon is -4, as 
shown in H 4 C; its highest combining value is +4, as shown 
in C0 2 . 

In all the cases referred to it will be seen that the total 
range, from highest to lowest, of the algebraic combining 
value of each element is just 8 units. 

That this is not mere chance but the result of natural law 
may be inferred from the fact that the quantity of any 
oxidizing agent required to increase the algebraic combining 



THE ALGEBRAIC COMBINING NUMBERS OF ATOMS 95 

number of any atom from +1 to 4-5 is the same as the 
quantity required to increase it from —4 to 0, or from —1 to 
+3, or from —2 to +2, or from —3 to +1, or from +2 to +6, or 
from +3 to +7, and it is twice as great as the quantity of 
oxidizing agent required to raise the algebraic combining 
number of any atom from —4 to —2, or from —2 to 0, or 
from to -i-2, or from +1 to +3, etc. To increase the 
algebraic combining number of nitrogen from —3 to +5, as 
when ammonia is converted into nitric acid, requires just 8 
units of oxidizing power, and to change H 2 S into H 2 S0 4 also 
requires just 8 units of oxidizing power, because the value 
of the sulphur in H 2 S is evidently —2 and that of the sulphur 
in H 2 S0 4 is evidently +6 (see next paragraph). 

198. As one half of all the bonds of all the atoms com- 
posing any molecule are positive bonds and the other half 
negative bonds, it follows that the algebraic sum of all must 
in every case be 0. If, therefore, the algebraic combining 
number of two out of three elements in any molecule be 
known, the combining number of the third is easily found, 
for it must be in every case the difference between and the 
algebraic sum of the combining numbers of the other two. 

In H 2 S0 4 we have eight negative oxygen bonds, because 
each of the four oxygen atoms has two negative bonds ; the 
two hydrogen atoms have together two positive bonds ; the 
sulphur atom must, therefore, have six positive bonds, for —8 
and -i-2 and +6 added together make the sum of 0. 

199. The algebraic combining number of any free atom is 
of course 0. It cannot be known how many bonds any atom 
has, nor what its polarity is, except from its actual com- 
binations, for we have seen that many elements have a 
variable valence and at least thirteen elements are positive 
in some compounds and negative in others. Thus, a free 
chlorine atom is neither positive nor negative and its actual 
combining number is 0. If it enters into chemical com- 



96 A CORRESPONDENCE COURSE IN PHARMACY 

bination with hydrogen, or with any metal, it then assumes 
negative polarity, and its algebraic combining number will 
be —1 ; but if it enters into direct combination with oxygen 
in the formation of molecules of NaOCl, the chlorine atom 
assumes positive polarity and its value will be +1, and if it 
forms KC10 3 the chlorine assumes an algebraic combining 
number of +5. 

The carbon atom in any carbon compound usually has 4 
bonds. In the free or uncombined state its algebraic com- 
bining number is 0. When it is united to four hydrogen 
atoms, H 4 C, the carbon atom has a combining number of —4; 
if it holds three (positive) hydrogen atoms and one (negative) 
chlorine atom, H 3 CC1, its value is —2; if it holds two (posi- 
tive) hydrogen atoms and two (negative) chlorine atoms, 
H 2 CC1 2 , its value is 0; if it holds one hydrogen atom and 
three chlorine atoms, its value is —2. 

200. Whenever two atoms of the same element are directly 
united to each other it must be assumed that they are held 
to each other by bonds of opposite polarities. Hence it 
follows that one of the hydrogen atoms in a molecule of 
hydrogen (composed of two atoms) must be positive and the 
other negative. In a molecule of oxygen containing two 
atoms of that element we must conclude either that each 
atom has one positive and one negative bond or that one has 
two positive bonds and the other two negative bonds, for 
the algebraic sum of all the bonds in any molecule must 
always be zero. 

201. In the molecule HN 3 it is impossible to escape the 

/N" < . 
conclusion that the atomic linking must be H — N v 1 1 , which 

shows that the hydrogen atom with its one positive bond is 
united to one of the nitrogen atoms by one negative nitrogen 



THE ALGEBKAIC COMBINING NUMBEKS OF ATOMS 97 

bond, while of the other six nitrogen bonds three are positive 
and the other three negative. 

In HO OH we assume that the algebraic sum of the bonds 
of both oxygen atoms together must be —2, because the 
hydrogen atoms together must be +2 and the total must be 
; hence one of the oxygen atoms must have one positive 
and one negative bond and the other oxygen atom must have 
two negative bonds. The two bonds by which the two oxygen 
atoms are held to each other must therefore be one of them 
positive and the other negative. We must assume that the 
algebraic sum of the bonds by which any two atoms of the 
same element are held in direct combination with each other is 
always zero, because one half of them must be positive and the 
others negative, 

202. To find the algebraic combining number of any atom 
in any molecule of simple structure is usually an easy task, 
unless two or more atoms of one and the same element are 
directly united to each other. The student can readily find 
the combining numbers of combined elements from the 
atoms known to have constant values, such as H, K, Na, Li, 
Ba, Sr, Ca, Mg, Al, B, Ag, Zn, and F; also from the 
oxygen in any molecule, unless two oxygen atoms are united 
directly to each other; also from the negative atoms of 
chlorine, bromine, iodine, sulphur and nitrogen. 

Since a varying algebraic combining number is possible 
only to elements having positive polarity, the student should 
find the algebraic combining numbers of any atom of such 
an element from the atom or atoms with which it is in direct 
combination; or, in other words, from any atoms in the 
molecule the algebraic combining values of which are con- 
stant and, therefore, known. 

203. The algebraic combining number of the acidic 
element in any inorganic acid composed of that element 
together with hydrogen and oxygen, is found by deducting 



98 A CORRESPONDENCE COURSE IN PHARMACY 

the algebraic sum of the oxygen and hydrogen bonds from 0. 
The oxygen atoms in the molecule of such an acid are the 
only atoms having exclusively negative bonds ; the hydrogen 
atoms are all positive, and either all or a majority of the 
bonds of the acidic element are positive. 

In HN0 3 the N must have five positive bonds; in H 3 P0 4 
the P must have five positive bonds. But in Na 2 AsH0 3 
the As has an algebraic combining number of only +3, 
although it has five bonds, for the structure of the molecule 

H 

is known to be N ^ /As= ; and in KPH 2 2 the P has an 

algebraic combining number of only +1, although it has five 

H 

I 
bonds, because the structure is KO — P = 0. 

I 
H 

204. In the molecule commonly but erroneously written 
CaS 5 we know that the algebraic sum of all the bonds of the 
five sulphur atoms must be —2, because Ca (as shown by its 
position in the periodic system) can never have any other 
value than +2. No compound of calcium is known in which 
that metal has any other combining value than 2. It follows 
that the two positive calcium bonds must be in combination 
with two negative sulphur bonds and that of all the remain- 
ing sulphur bonds one-half must be positive and one-half 
negative. This leads to the structural formula 

in which the central sulphur atom is acidic and has six 
positive bonds, while all the other sulphur atoms each have 



THE ALGEBRAIC COMBINING NUMBERS OF ATOMS 99 

two negative bonds, the molecule being perfectly analogous 
to CaS0 4 , which has the structure 

There is a molecule erroneously written K 2 S 3 which has 
the structure 

K— S— S— S— K. 

In this molecule the central sulphur atom is acidic and 
has a combining value of +2, while all the other four sulphur 
bonds are negative, because the structure is perfectly anal- 
ogous to that of KOSOK. 

There is a compound erroneously called ''hyposulphite of 
sodium," which is commonly represented as Na 2 S 2 3 . But 
with the aid of our conception of the algebraic combining 
numbers of the component atoms of molecules we can readily 
see that the structure must be 

NaS\ Q ^0 nr mO\„//8 
NaO/%0 or NaO/%0 

and chemists now write it Na 2 S0 3 S, to show that one 
sulphur atom performs the acidic function while the other 
performs the same function as any of the oxygen atoms in 
Na 2 S0 4 . 

205. The algebraic sum of all the carbon bonds in any 
molecule composed of carbon, hydrogen and oxygen (and a 
vast majority of organic substances are composed of those 
elements) is at once found by subtracting the algebraic sum 
of all the bonds of the atoms of hydrogen and oxygen from 0. 
It is further known that all the carbon atoms in such com- 
pounds have each four bonds. The total number of positive 

LOFa 



100 A CORRESPONDENCE COURSE IN PHARMACY 

carbon bonds and the total number of negative carbon bonds 
can, therefore, be readily found. It is also known that the 
algebraic sum of all bonds by which any of the carbon atoms 
are united to each other must be 0. These facts are helpful 
in determining the actual atomic linking. 



Test Questions 

1. Define valence. 

2. What is the valence of the boron in H 3 B ? in B 2 3 ? 

3. What is the difference arithmetically between the valence 
of the boron in H 3 B and in B 2 3 ? 

4. What is the difference between the algebraic combining 
number of the boron in H 3 B and the boron in B 2 3 ? 

5. What are the respective valences of the elements form- 
ing a binary hydrogen compound ? 

6. How do you find the valence of each of the two elements 
in any oxide ? 

7. Can you name an element having a valence of 10 ? 

8. What is the number of chlorine atoms in the chloride 
of an element having a valence of 8 ? 

9. What is the number of hydrogen atoms in the hydride 
of an element having a valence of 6 ? 

10. How many chlorine atoms are there in the chloride of 
a heptad ? 

11. How many oxygen atoms are there in the oxide of a 
tetrad and how many in the oxide of a pentad ? 

12. Name two octads. 

13. How many bonds has a potassium atom ? 

14. How many bonds has aluminum ? 

15. Name the number of bonds of the zinc atom. 

16. Draw a figure showing the atomic linking of As 2 3 ; 
C 2 H a . 



THE ALGEBRAIC COMBINING NUMBERS OF ATOMS 101 

17. Under what circumstances can the valence of an 
element vary ? 

18. State the number of bonds of each element in the 
molecule OSbCl. 

19. State the number of bonds of each element in (a) 
KN0 3 ; (b) Na 4 P 2 7 ; (c) CaS0 4 ; (d) CaH 2 S0 5 ; (e) H 5 P0 5 ; 
(f) H 3 P0 4 ; (g)HP0 3 ; (h) H 3 P0 3 ; (i)HP0 2 ; (j) HPH 2 2 ; 
(k) H 2 PH0 3 ; (1) KMn0 4 ; (m) K 2 Mn0 4 . 

20. State which of the following molecular formulas are 
right and which are wrong: (a) AgCl 3 ; (b) KO; (c) Mg 2 3 ; 
(d)H,0; (e)Na 2 S 5 . 

21. What is the valence of the sulphur in S0 2 and what 
is the algebraic combining number of each of the two ele- 
ments in that molecule ? 

22. What is the algebraic combining number of the 
sulphur in H 2 S ? 

23. What is the difference between the valence of the 
sulphur in H 2 S0 2 and in H 2 S and what is the difference 
between the algebraic combining number of the S in those 
two molecules ? 

24. What is the algebraic combining number of the N in 
HN0 3 and in H.lSTBr ? 

25. What is the algebraic sum of the carbon bonds in 
C 6 H 10 O 5 ? 

26. What is the algebraic combining value of the Br in a 
bromide ? 

27. Can bromine under any circumstances have a higher 
algebraic combining number, and if so, when ? 

28. If the valence of sulphur, with negative polarity, is 
2, what is the highest possible algebraic combining number 
of sulphur ? 

29. If zinc phosphide is Zn 3 P 2 , then what is the 
highest possible algebraic combining number of phos- 
phorus ? 



102 A CORRESPONDENCE COURSE IN PHARMACY 

30. What is the algebraic combining number of uncom- 
bined carbon ? 

31. State the algebraic combining numbers of the three 
different elements in Na 2 S 2 3 . 

32. What is the algebraic sum of the carbon bonds in 
HC 2 H 3 2 ? 



LESSON NINE 

XIII 

Chemical Notation 

206. We have already made use of several chemical symbols 
and self-explanatory formulas. Before proceeding further 
we will now learn something of the principles governing the 
construction of symbolic formulas. 

In order to represent at a glance the composition and 
structure of molecules a system of chemical notation was 
invented by Berzelius, which is still in use, modified and 
adapted to correspond to the development of the science of 
chemistry since his day. 

207. Each atom of any given element is represented by a 
specific symbol unlike the symbol of any other element. 
The symbol consists of one or two letters which are the 
initials of the latinic or other names of the elements. Two 
letters are used for some of the symbols in cases where the 
names of two or more elements begin with the same letter. 
The additional letter used is not always the second letter of 
the name, but one which will best serve to make the symbol 
distinctive. As the names of chlorine and chromium both 
begin with Ch, their symbols are made 01 and Or. 

The first letter of any symbol of two letters is a capital 
letter; the second is not. 

208. The symbol of any element stands not merely for its 
name, but for one atom of it and for its atomic weight or 
combining mass. 

103 



104 A CORRESPONDENCE COURSE IN PHARMACY 

Thus S, the symbol for sulphur, means one atom of sulphur 
and also 32 parts of sulphur. 

209. Symbolic formulas are constructed out of one. or more 
symbols together with one or more numerals, or of two or 
more symbols with or without numerals. 

KI is a symbolic formula because it is composed of two 
symbols, K and I ; Cl 2 is a formula because it is composed 
of a numeral as well as a symbol; 2C1 is also a formula for 
the same reason; 3 , H 2 0, OaCl 2 and HN0 3 are also sym- 
bolic formulas. 

Symbolic molecular formulas of compounds are so con- 
structed that they show not only all of the elements com- 
posing them but the number of atoms of each. 

210. The numerals used are of two "kinds — large and small. 
A large numeral placed in front of a symbol multiplies it, 

but it also indicates that the atom represented by the symbol 
is a free or uncombined atom. Thus 90 means nine oxygen 
atoms not united to one another. A small numeral placed 
after a symbol also multiplies the atom, but it signifies that 
all the atoms are in chemical combination either with one 
another or with other atoms. Thus 3 means three atoms 
of oxygen in combination with one another, or, in other 
words, a molecule of ozone. The formula 30 3 means three 
molecules of ozone each containing three atoms of oxygen; 
but 90 means nine single oxygen atoms and not three 
molecules of ozone. 

A large numeral in front of any symbolic molecular 
formula multiplies the whole molecule, but a small numeral 
is never used to multiply a molecule; the latter is placed to 
the right of the symbol which it is intended to multiply and 
a little below the line, as in 3 . Thus, the formula O 6 H 10 O 5 
means one molecule composed of six carbon atoms, ten 
hydrogen atoms and five oxygen atoms, and 2C^H 10 O 5 means 
two such molecules. 



CHEMICAL NOTATION" 105 

The following examples will suffice to make these things 
clear : 

Hg stands for one atom of mercury. 

Hg also stands for one molecule of mercury, because each 
molecule of mercury contains but one atom. 

2H means two free hydrogen atoms. 

3H means three free hydrogen atoms. 

H 2 means two hydrogen atoms united to each other to 
form one molecule. 

2H 2 means two molecules of hydrogen of two atoms each. 

4H01 means four molecules of hydrogen chloride. 

5H 2 means five molecules of water. 

211. How to Write Molecular Formulas. The symbols 
representing the elements composing the molecules are to be 
written, and where more than one atom of the element enters 
into the molecule the number of atoms of each element is indi- 
cated by an "inferior" (lower) numeral to the right of the 
symbol a little below the line, as shown in Fe 2 3 , a molecule 
consisting of two atoms of iron and three atoms of oxygen. 

In writing the molecular formula of a binary compound 
the positive element (or ion) is always to be placed first and 
the negative element (or ion) last. Hence, the symbol of 
the metal is always written first in the molecular formula of 
any binary compound of a metal. 

In writing the molecular formula of any compound con- 
taining three or more elements, the ions, if known, are placed 
in the same order as in the molecular formulas of binary 
compounds. Such compounds must contain at least one 
ion composed of more than one element, and the elements of 
each ion are written in the same order as the jons themselves — 
the positive elements before the negative elements — when- 
ever practicable ; or the elements are written in the order 
determined by their respective valences and indicative of the 
actual atomic linking, so far as practicable. 



106 A CORRESPONDENCE COURSE IN PHARMACY 

Two elements having or exercising the same polarity in any 
molecule may be placed beside each other for the sake of con- 
venience and brevity, if the formula is not intended to show the 
relative positions of all the atoms but only to show the ions. 
But whenever the whole system of atomic linking is to be 
shown it is evident that any two atoms placed immediately 
beside each other must be of opposite chemical polarity with re- 
spect to each other. We write KJST0 3 for convenience, because 
K is the positive ion and N0 3 is the negative ion ; but K is not 
the only positive atom, for N is also of positive polarity, so that 
K is not directly united to N and the actual atomic linking is 
therefore not shown in the formula KN0 3 . If the atomic 
linking of potassium nitrate is to be shown the formula should 
be written KOJST0 2 , for the K is directly united to one atom 
of oxygen and that atom of oxygen is at the same time directly 
united to the N, which, having five bonds, also holds the 
other two oxygen atoms in direct combination with itself. 

Molecular formulas are sometimes written in a manner 
inconsistent with the foregoing rules, because these rules are 
not explicitly stated in the text-books, although the commonly 
written molecular formulas in nearly all cases conform to 
them and no good reasons apparently exist which explain 
the few exceptions. 

H 4 NOH is a correctly written molecular formula, because 
the nitrogen atom is admittedly directly united to four 
hydrogen atoms and to the oxygen atom, and the fifth hydro- 
gen atom is directly united to the oxygen atom and not to 
the nitrogen; but the formula NH 4 HO, often seen, is incon- 
sistent because it separates the nitrogen from the oxygen. 
The actual structure of this molecule is 

H 

!>N-0-H 

i 
H 



CHEMICAL DOTATION 107 

which may well be represented by H 4 NOH, but not by 
NH 4 HO. 

The formula NH 4 C1 is inconsistent, because the nitrogen 
is really directly united to the CI and the 01 is not united to 
hydrogen, for the nitrogen atom has five bonds and the atoms 
of hydrogen and chlorine have only one bond each, so that 
the correct formula is H 4 NC1, and four of the nitrogen 
bonds (holding the hydrogen atoms) are of negative chemical 
polarity, while the fifth bond (holding the chlorine atom) is a 
positive bond. 

212. Large (or ordinary) figures or numerals are used 
to multiply single molecules. A true molecule has but one 
(or a continuous or undivided) system of atomic linking. 

Two or more molecules may be held to each other in some 
way not yet understood (not consistent with our conception 
of atomic valence), and such molecular combinations are 
represented by formulas which show the several combined 
molecules by means of their own respective molecular 
formulas and numerals indicating the number of molecules 
of each kind. 

The formula BaCl 2 .2H 2 or Ba01 2 +2H 2 represents a 
combination of one molecule of Ba01 2 with two molecules 
of H 2 0. This molecular combination has three separate 
and distinct systems of atomic linking — one for the Ba01 2 
and another for each of the two molecules of water. 

The formula 2K 2 C0 3 +3H 2 represents a molecular com- 
bination of two molecules of K 2 C0 3 with three molecules of 
water. This combination has five separate systems of atomic 
linking. 

All molecular combinations have as many separate systems 
of atomic linking as the number of molecules they contain, 
for each molecule has its own. 

When any symbols or molecules are embraced in parentheses 
and a numeral is placed outside the parentheses, that numeral 



108 A COKEESPONDENCE COUKSE IN PHAKMACY 

multiplies all that is enclosed within the parentheses. Thus 
3(2K 2 C0 3 +3H 2 0) means three times 2K 2 C0 3 +3H 2 0; Fe 
(S0 4 ) 3 means Fe united to three times S0 4 ; and the expres- 
sion 4MgC0 3 .Mg(OH) 2 .5H 2 means a combination of 4 mole- 
cules of MgC0 3 with one molecule of Mg(OH) 2 and 5 of water. 
The formula K 4 Fe(CN) 6 represents a chemical compound 
known as ferrocyanide of potassium. It is recognized as a 
ferrous compound, which means that the iron atom in it has 
two bonds. The potassium atoms have one bond each. The 
combination consists of 4 potassium atoms, one iron atom 
and 4 times the group CN. The group ON, consisting of the 
tetrad C and the triad N, is a univalent radical. It is impos- 
sible to escape the conclusion that there must be six inde- 
pendent systems of interatomic linking in this combination, 
or that the only formula for it which is consistent with our 
conceptions of atomic valence must be 4KCN+Fe(CN) 2 . 

213. Empiric formulas are formulas expressing in the 
simplest terms the relative numbers of the atoms of each 
element contained in a compound. 

The empiric formula for acetic acid is CH 2 0. This simply 
indicates that we have in the composition of acetic acid two 
hydrogen atoms and one oxygen for each carbon atom. It 
does not show the actual number of atoms of each kind con- 
tained in one molecule. 

214. Molecular formulas show the actual number of atoms 
of each kind which form one molecule of the substance. 

The molecular formula of acetic acid is not CH 2 but 
C 2 H 4 2 , or HC 2 H 3 2 , or H 3 C.C0.OH, for the vapor den- 
sity of acetic acid proves that its molecular weight must be 
the sum of the weights of two carbon atoms, four hydrogen 
atoms, and two oyxgen atoms, which would be most simply 
expressed by 2 H 4 2 . The formula HC 2 H 3 2 is one which 
shows that one of the four hydrogen atoms can be replaced by 
a metal or that the two ions of acetic acid are H and C 2 H 3 2 . 



CHEMICAL NOTATION 109 

215. The constitutional or structural formula of any com- 
pound is one that shows the relative positions of the atoms, 
or their grouping, or their interatomic linking. The struc- 
tural or constitutional formula for acetic acid is H 3 C.CO.OH, 
because the three recognized atomic groups composing its 
molecule are methyl (H 3 0), carbonyl (CO), and hydroxyl (OH). 

A graphic structural formula showing the interatomic 
linking of acetic acid in detail is 

H 

I II 
H— C— C— 0— H 

I 
H 

216. To construct the molecular formula of any binary 
compound is an easy problem if the valence of each of the 
two elements is known. To do so, multiply the symbol of each 
element by the valence of the other: 

The molecular formula of bismuthous oxide must be 
Bi 2 3 . To arrive at it, first write down Bi for bismuth and 
for the oxygen. Then, as the valence of bismuthous 
bismuth is 3, write that numeral after the 0, and as the 
valence of is 2, we write that numeral after the Bi. 

To construct the molecular formula of any compound of 
two known ions is an equally simple proposition: First 
write the two ions and then multiply each ion (or radical) by 
the valence of the other. 

Thus, the molecular formula of tricalcium phosphate is 
Ca 3 (P0 4 ) 2 , because the valence of Oa is 2 and that of P0 4 is 3. 
The valence of P0 4 is 3, because the algebraic combining 
number of P in all phosphates is +5, and the valence of the 
oxygen atom is —2, so that P0 4 has five phosphorus bonds 
and eight oxygen bonds and the difference between 5 and 8 
is 3, representing 3 oxygen bonds not in combination with 
the P. 



110 A CORRESPONDENCE COURSE IN PHARMACY 

Tlie number of bonds of the positive ion must be the same 
as the number of bonds of the negative ion, or the total bonds 
of each must be a common multiple of the respective valences 
of both. Ca 3 represents 3 calcium atoms which together 
have 6 bonds, and (P0 4 ) 2 represents twice P0 4 , having also a 
total of 6 bonds. 

217. The student can readily learn to write structural 
molecular formulas showing the combining values and inter- 
atomic linking, and also the common molecular formulas 
from the following : 

Each unit of combining value is represented by a line 
or dash, which is a solid line if the unit or "bond" is of 
positive polarity but dotted if the bond is a negative one. 

The algebraic combining values range from +8 to —4. 

Osmium forms a tetr oxide which may be represented as 



0:::=Os=:::0 





Chlorine, iodine and manganese may each exercise a value 
of +7 in the compounds called perchlorates, periodates and 
permanganates : 



..o 


..O 


K C1=::::0 

"•0 


K Mn— .:::0 

"'0 


Potassium Perchlorate. 


Potassium Permanganate. 



A combining value of +6 is exercised by S in sulphuric 



CHEMICAL NOTATION 



111 



compounds, Or in chromic acid and chromates, Mn in man- 
ganates, Mo in molybdates and Fe in ferrates : 



H 



S 



H 0. • ^ 

Sulphuric Acid. 



•O Na 0. ...O 

■ Na ..■•'• ^'••'•O 

Sodium Chromate. 



A combining value of +5 is shown by N in nitric acid and 
other nitrates, P in phosphoric compounds, As in arsenic 
compounds, Sb in antimonic and Bi in bismuthic compounds; 
also by 01 in chloric, Br in bromic and I in iodic compounds : 



.0 



Q> 



CI 



6> 



H<" ~ 5 



;:0 


\ 1 / 
P 




•'••• 


cK' "Qt 


Mercuric Nitrate. 




Phosphoric Chloride. 


.0 . 






Bi™0 "^Bi 

X"o ■"/ 

"0" 




..,0 

K_ Cl^f 

^0 


Bismuthic Oxide. 




Potassium Chlorate. 



A combining value of +4 is exercised by C in carbonic 
compounds, Si in silicic and Sn in stannic compounds ; by 
Pt in platinic compounds, Oe in eerie, Pb in perplumbic, S in 
sulphurous compounds, Fe in ferrites, Mn in manganites and 
in Mn0 2 , Mo in Mo0 2 and by N in N0 2 . 



0:::~C=:::::0 

Carbonic Oxide. 






o^ 



;pt" 

Platinic Chloride. 



112 



A CORRESPONDENCE COURSE IN PHARMACY 



0::::=Pb=::::0 
Peroxide of Lead. 



H 0— - b ° 

Sulphurous Acid. 



An algebraic combining value of +3 is exercised by B in 
boric compounds, Al in all its compounds, Fe in ferric halides 
and salts, Ni in nickelic and Co in cobaltic compounds, Cr 
in Cr 2 3 and several other compounds, Mo in Mo 2 3 , Mn in 
Mn 2 3 , MnOl, etc., Au in auric compounds; by N" in nitrous, 
P in phosphorous, As in arsenous, Sb in antimonious and Bi 
in bismuthous compounds ; and by CI in chlorous, Br in bro- 
mons, and I in iodous compounds: 



H- 



B 0- 

. 1 


-H 


H Al— "0- 

! 


6 




6 


i 

H 

Boric Acid . 




i 

H 
Aluminum Hydroxic 


01 Fe CI 




.. • o .... 


1 

tii 

Ferric Chloride. 




Cr^ ~Cr 

"• o -" 

Dichromium Trioxide. 



H 



; o N= 


::::0 


Nitrous Acid. 




...0.... 

"•o"* 

Chlorous Oxide. 


CI 



Na— -^ — - U 

Sodium Phosphite. 



01 1- 

I 



■CI 



CI 
Iodine Trichloride. 



CHEMICAL NOTATION 



113 



A combining value of +2 is exercised by Mg, Ca, Sr, Ba, 
Zn and Cd in all their compounds; by Cu in cupric and Hg 
in mercuric compounds ; by Fe in ferrous, Ni in nickelous, 
and Co in cobaltous compounds; by Or in chromous, Mo in 
molybdous and Mn in manganous compounds; by Sn in 
stannous and Pb in plumbic compounds ; by Pt in platinous 
compounds; by C in carbonous compounds; by S in hypo- 
sulphurous compounds ; and by N in NO : 



Mg=::::0 




01 Ca CI 


Magnesium Oxide. 




Calcium Chloride. 


; o B 


-H 


H 
1 


Barium Hydroxide. 




i 

6 

6 

i 

H 

Ferrous Sulphate. 


C— :::0 




Na -^q 

Na 0- -^ 


Carbonous Oxide. 








Sodium Hyposulphite 



An algebraic combining value of +1 is exercised by H, Li, 
Na, K, and Ag in all their compounds; by Cu in cuprous, 
Hg in mercurous, Au in aurous compounds ; by CI in hypo- 
chlorous, Br in hypobromous and I in hypo-iodous com- 
pounds; by N in hyponitrous and P in hypophosphorous 
compounds : 



114 



A CORRESPONDENCE COURSE IN PHARMACY 



H H 

Water. 

Hg— -01 
Mercurous Chloride. 

JSTa— -O CI 

Sodium Hypochlorite. 



H 



K Pr 



::0 



H 



Potassium Hypophosphite. 



An algebraic combining value of is exercised by one of 
the oxygen atoms in HO OH and by one of the sulphur atoms 
in H S S H; also by in many compounds, as in 

CI 



H— C 



■H 



CI 
A combining value of -1 is shown by F in all fluorides, CI 
in all chlorides, Br in all bromides and I in all iodides : 



I Br 

Iodine Monobromide. 



<* 



?. 
""..* 



X 

<$■■■ "■■& 

Iodine Pentafluoride. 



.1 

N^ I 

I 

Nitrogen Iodide. 

"X 

Sulphur Tetrachloride. 



F has a combining value of -1 in all its compounds; 01 
has a value of —1 in all its compounds with all elements except 
F and ; Br exercises the combining value of -1 in all the 
compounds it forms with all elements except 01, F and ; I 
exercises that value in all the compounds it forms except 
with Br, 01, F and 0. 



CHEMICAL NOTATION 115 

A combining value of -2 is exercised by in all the com- 
pounds in which it is directly unjted to any other element. 
In other words, it exercises that value in all cases except 
where two oxygen atoms are directly united to each other, 
in which event one of the oxygen atoms has a value of 0. 

Sulphur, whenever it exercises negative polarity, has a 
combining value of —2; it accordingly has a value of —2 
whenever it is in direct combination with any element except 
0, F, 01, Br and I. • 

The carbon atom exercises a combining value of -2 in all 
compounds in which it has one positive and three negative 
bonds, as in H 3 CC1. 

The combining value of -3 is exercised by B in H 3 B ; by N 
in all compounds in which the nitrogen atom is negative and 
not united to another nitrogen atom, and it, therefore, has 
that value in H 3 N and in all ammonium compounds, in 
alkaloids, and in numerous organic compounds. Negative P, 
negative As and negative Sb also have a combining value of —3: 

H 



N Sr— »oi 




♦<■] 


^Cu ^ 
As ••"• — Cu — '•'•• As 


H 


""^Cu^"" 


Ammonium Chloride. 


Cupric Arsenide. 


H 




! 


H 


6 


< ! > 


<s i > 

":n."' 


*:n_....o.. n^ 


^-" "^-fr 


1 

H 


Ammonium Hydroxide. 


Ammonium Nitrate. 



116 A CORRESPONDENCE COURSE 1ST PHARMACY 

A combining value of —4 is exercised by the in H 4 C and 
by Si in H 4 Si. 

H H 

j ! 

H b H H— ••&•• — H 



H H 

Marsh Gas. Hydrogen Silicide. 

XIV 

Chemical Nomenclature 

218. "We have already learned that classes of binary com- 
pounds are given generic titles ending with ide, as, for 
instance, oxides, sulphides, chlorides, bromides, etc; and 
that salts are named after their corresponding acids, such 
as sulphates, named after sulphuric acids; nitrates, named 
after nitric acids; sulphites, named after sulphurous acid; 
nitrites, after nitrous acid, etc. 

The adjectives used in the nomenclature of inorganic 
chemical compounds and the relation of these adjectives to 
the other technical terms require careful consideration, and 
also the prefixes which are employed wherever necessary. 

The substantive nouns ending in ide, ate and ite are derived 
from the names of the negative radicals, whereas the adjec- 
tives used are derived from the names of their positive radi- 
cals, or from positive elements. 

219. In the chapter on Atomic Valence, we learned that 
many elements when exercising positive polarity may have 
two, three or four valences, and that, accordingly, they may 
have several oxides or sulphides or chlorides or hydroxides. 
These must be distinguished from one another in a system- 
atic way. 



CHEMICAL NOMENCLATURE 117 

220. The Endings ic and ous. When any element exercises 
two different combining values, the higher value is indicated 
by an adjective ending in ic and the lower combining value 
is indicated by an adjective ending in ous. Carbon, mercury 
and iron will serve as examples to illustrate this rule. 

Carbonic carbon is positive carbon with an algebraic com- 
bining number of +4; carbonous carbon is positive carbon 
with an algebraic combining number of +2. Positive carbon 
has no other algebraic combining numbers. 

Mercury has two combining values ; its higher value is +2 
and is called mercuric mercury, while its lower combining 
number is 1 and mercury with that combining number is 
called mercurous mercury. 

Carbonic oxide is C0 2 , carbonous oxide is CO, mercuric 
chloride is HgCl 2 , and mercurous chloride is HgCl. 

When iron exercises basic functions and when it forms 
binary compounds, it may have a combining value of either 
+2 or +3. Iron with a value of +2 is called ferrous iron ; 
iron with a value of +3 is called ferric iron. 

221. The Prefixes hypo and per. When an element exer- 
cising positive polarity has three different combining values, 
the highest is indicated by an adjective ending in ic, the 
middle value is indicated by an adjective ending in ous, and 
the lowest value is indicated by an adjective ending with ous 
in addition to the prefix hypo, which means below or under. 

Sulphur, for instance, is sulphuric sulphur when it 
exercises the algebraic combining number of +6 ; it is sul- 
phurous when it has the combining number +4; it is hypo- 
sulphurous when it has the combining number of +2. 

When an element exercising positive polarity has four 
different combining values, the lowest value is indicated by 
the prefix hypo and the ending ous, the next higher value is 
indicated by the ending ous without any prefix, the third 
value is indicated by an adjective ending in ic without any 



118 A CORRESPONDENCE COURSE IN PHARMACY 

prefix, and the fourth and highest value is indicated by the 
ending ic and the prefix per. Thus, positive chlorine forms 
hypochlorous compounds, chlorous compounds, chloric com- 
pounds and perchloric compounds. 

222. But even these devices are not always sufficient. We 
shall accordingly learn now all the prefixes commonly employed 
in inorganic chemical nomenclature. They are as follows : 

(a) Prefixes derived from Greek numerals: 
Mono or mon, meaning one, single or once. 
Di or dis, meaning two or twice. 

Tri or tris, meaning three or thrice. 

Tetra, meaning four. 

Penta, meaning five. 

Hexa, meaning six. 

Hepta, meaning Seven. 

Octo, meaning eight. 

Deca, meaning ten. 

(b) Prefixes derived from Latin numerals: 
Un or uni, meaning one or single. 

Duo, bi, bin, or bis, meaning two or twice. 
Ter or tri, meaning three or thrice. 
Quadri or quadra, meaning four. 
Quinque or quinqui, meaning five. 
Sexa or sexi, meaning six. 
Septi or sept, meaning seven. 
Octo or octi, meaning eight. 

(c) Other prefixes: 

Hypo, meaning under, lower or below. 

Sub, meaning under, lower or below. 

Per, meaning thorough, through or to the full extent. 

Meta, meaning altered, different, after or beyond. 

Para, meaning changed, different or altered. 

Ortho, meaning straight, regular, common, usual or original. 

Pyro, meaning as produced by fire or high heat. 

Thio, from theion (sulphur), meaning containing sulphur. 

The following illustrations will suffice to render clear the 
mode of employment of the foregoing prefixes : 

A monochloride is a chloride containing but one chlorine 



CHEMICAL NOMENCLATURE 119 

atom ; a dioxide is an oxide containing two oxygen atoms ; a 
tri-iodide contains three iodine atoms; a tetroxide contains 
four oxygen atoms; a pentafluoride contains five fluorine 
atoms ; a hexachloride contains six chlorine atoms ; a hep- 
toxide contains seven oxygen atoms. 

A bicarbonate contains twice as large a proportion of the 
carbonate radical 00 3 as a carbonate contains in proportion 
to the basic element, as shown by the molecular formulas 
KHOO3 an d K 2 00 3 , in which K is the basic element. 

Subsulphate of mercury contains a smaller quantity of the 
sulphate radical S0 4 in proportion to the mercury than the 
sulphate of mercury contains. Subnitrate of bismuth is a 
name given to OBiN0 3 , containing the N0 3 only once, while 
bismuth nitrate is Bi(N0 3 ) 3 . 

A thiocarbonate is a carbonate in which the oxygen is in 
part or wholly replaced by sulphur. A thiosulphate is a 
sulphate containing a larger proportion of sulphur than is 
contained in the other sulphates, some or all of the oxygen 
of the sulphate being replaced by sulphur atoms. Thus, 
sulphate of calcium is CaS0 4 , while thiosulphate of calcium 
is OaSS 4 , and other calcium thiosulphates are CaS0 3 S, 
CaS0 2 S 2 , and CaSOS 3 . 

223. Meta-compounds. The prefix meta when used in 
connection with hydroxides and salts has a specific meaning. 
It signifies a compound formed by the removal of the ele- 
ments of water from another compound of normal structure. 

A normal hydroxide or a hydroxide of normal composition 
contains no hydrogen or oxygen, except the hydrogen and 
oxygen of its hydroxyl. In other words, it contains an equal 
number of atoms of hydrogen and oxygen, and every hydrogen 
atom in such a hydroxide is directly united to an oxygen atom. 

Thus, ferrous hydroxide is Fe(OH) 2 , because ferrous iron 
is a diad and can therefore hold in combination two groups 
of hydroxyl, OH. Normal ferric hydroxide is Fe(OH) 3 , 



120 A CORRESPONDENCE COURSE IN PHARMACY 

because ferric iron is a triad and can accordingly hold in 
combination three hydroxyl groups. But OFeOH is a meta- 
hydroxide formed out of Fe(OH) 3 by its dissociation, result- 
ing in the formation of one molecule of water, H 2 0, and one 
molecule of the OFeOH, which is all that remains of the 
Fe(OH) 3 when one molecule of water has been split off from it. 

Normal sulphuric hydroxide or normal sulphuric acid is, 
of course, S(OH) 6 , because sulphuric sulphur is a hexad and 
can hold six hydroxyl groups. But if one molecule of water 
be split off from the S(OH) 6 , we would have (HO) 4 SO left, 
which is mono-meta-sulphuric acid, or mono-m eta-sulphuric 
hydroxide, the prefix mono indicating that only one molecule 
of water was split off. But if two molecules of water be 
split off from S(OH) 6 or (HO) 6 S, which is the same thing, 
then di-meta-sulphuric hydroxide or di-meta-sulphuric acid 
is formed, the formula of which is (HO) 2 S0 2 or H 2 S0 4 , 
which is our common sulphuric acid. A tri-meta-sulphuric 
acid containing but one atom of sulphur is impossible, 
because if three molecules of water be split off from (HO) 6 S, 
the remainder would be simply S0 3 , which is not a hydrox- 
ide nor an acid, but sulphuric oxide. 

The name orthophosphoric acid means the common or 
ordinary phosphoric acid. The prefix ortho does not indicate 
its composition, but the ending ic indicates that the phos- 
phorus in it has the combining number +5, which is the 
highest of the three positive algebraic combining numbers 
possible to phosphorus. The formula for orthophosphoric 
acid is H 3 P0 4 or (HO) 3 PO. A normal phosphoric hydroxide 
is, of course, (HO) 5 P. Accordingly, it is evident that 
orthophosphoric acid is a mono-meta-acid, and the name 
mono-meta-phosphoric acid is sufficient to indicate the 
structure of the compound or its true molecular formula. 
The glacial phosphoric acid commonly called meta-phosphoric 
acid has the formula HP0 3 , or HOP0 2 . It is therefore a 



CHEMICAL NOMENCLATURE 121 

di-meta-acid or (HO) 5 P, or H 5 P0 5 with two molecules of 
water split off from it, leaving HP0 3 . What is commonly 
called pyrophosphoric acid is a phosphoric acid produced 
by heating orthophosphoric acid, or a pyrophosphate is 
obtained by heating the corresponding orthophosphate. The 
common phosphate of sodium is Na 2 HP0 4 . It is accord- 
ingly disodium monohydrogen mono-meta-phosphate. But 
the pyrophosphate of sodium is Na 4 P 2 7 . The name pyro- 
phosphate does not indicate the composition, whereas the 
explicit technical term sodium tri-meta-di-phosphate at once 
tells the whole story of its structure, for it tells us that the 
acidic element in the compound is phosphoric phosphorus. 
The term diphosphate tells us that it contains two phos- 
phorus atoms, and the term tri-meta informs us that it differs 
by three molecules of water from the normal structure of 
two molecules of sodium phosphate added together. Two 
molecules of normal phosphoric hydroxide added together 
would make the formula H 10 P 2 O 10 . . Three molecules of 
water split off from that formula would leave H 4 P 2 7 . The 
sodium salt corresponding to H 4 P 2 7 is Na 4 P 2 7 . 

Borax is a sodium penta-meta-tetra-borate, because it is 
the sodium salt formed out of a boric acid resulting from the 
splitting off of five molecules of water from four molecules of 
normal boric hydroxide. It is called a tetra-borate because 
it contains four boron atoms. A borate must, of course, be 
formed from boric acid, and boric boron has a valence of 3. 
Normal boric hydroxide is accordingly (HO) 3 B or H 3 B0 3 . 
Four molecules of H 3 B0 3 would be H 12 B 4 12 , and after split- 
ting off five molecules of water from H 12 B 4 12 , we would 
have H 2 B 4 7 left, which is penta-meta-tetra-boric acid, and 
the sodium salt of it is accordingly ]STa 2 B 4 7 . 

224. From the facts stated in the foregoing paragraphs, 
the student will see that hypochlorous fluoride would be C1F; 
hypochlorous oxide must be C1 2 ; hypochlorous acid must 



122 A CORRESPONDENCE COURSE IN PHARMACY 

be HOC1; potassium hypochlorite is KOOl; and calcium 
hypochlorite Ca(C10) 2 . 

Hypophosphorous oxide must be P 2 0. Hypophosphorous 
acid may be either HOP or it may be HOPH 2 0, in which the 
student can readily see that the algebraic combining number 
of the phosphorus is still +1. Phosphorous oxide must be 
P 2 3 ; phosphorous chloride must be PC1 3 ; and phosphorous 
acid may be either (HO) 3 P or HP0 2 , or it may be even 
(HO) 2 PHO, for in all of these formulas of acids it is clearly 
seen that the phosphorus atom has an algebraic combining 
number of +3. The student can readily see at once that 
H 5 P0 5 , H 3 P0 4 , HP0 3 , and H 4 P 3 7 must all be different kinds 
of phosphoric acid, because in every one of them the phos- 
phorus atom clearly has an algebraic combining value of +5. 

Upon examination of the formulas H 6 S0 6 , H 4 $0 5 , and 
H 2 S0 4 , it is seen that these formulas all represent different 
kinds of sulphuric acid, the first being normal sulphuric 
acid or sulphuric hydroxide, the second mono-meta-sulphuric 
acid, and the third di-meta-sulphuric acid, because in all of 
them the sulphur atom is seen to have a combining value 
of +6. 

The formula CaH 4 S0 6 evidently represents a calcium 
sulphate derived from normal sulphuric hydroxide. 
CaH 2 S0 5 is a sulphate derived from the mono-meta-sulphuric 
acid, and CaS0 4 is calcium di-meta-sulphate. FeH 2 S0 5 is 
ferrous mono-meta-sulphate, which is common ferrous sul- 
phate, or green vitriol, minus its water of crystallization. 

Test Questions 

1. What is the meaning of Ag ? 

2. Why is the symbol representing lead Pb instead of L ? 

3. What is I 2 and what is the difference between 21 
and I 2 ? 



CHEMICAL NOMENCLATURE 123 

4. What is the difference between 4H and 2H 2 and H 4 ? 

5. Which of the following formulas are correct and which 
are incorrect: (a) HgO; (b) Hg 2 0; (c) HgO a ; (d) Hg 3 ; 
(e)H 4 ; (f)0 4 ; (g) H 2 C1 2 ? 

6. Name the two ions of each of the following : ferrous 
chloride, ferric chloride, sodium nitrate, potassium hy- 
droxide, phosphoric acid, ammonium sulphate, ammonium 
chloride, arsenous oxide, antimonous sulphide, potassium 
antimonite. 

7. Write the molecular formulas of the following named 
compounds: (a) carbonic acid; (b) sodium carbonate; (c) 
calcium bromide ; (d) potassium fluoride ; (e) silver iodide , 
(f) nitrogen iodide; (g) barium sulphide; (h) calcium oxide; 
(i) sulphide of carbon ; (j) sulphide of trivalent arsenic ; (k) 
the sulphide of quinquivalent antimony; (1) the hydroxide 
of boron ; (m) three molecules of the sulphate of trivalent 
iron; (n) two molecules of aluminum sulphate; (o) seven 
molecules of magnesium hydroxide; (p) two molecules of 
bismuth nitrate, containing the bismuth as a triad. 

8. In which of the two molecules Bi 2 (00 3 ) 3 and (OBi) 2 C0 3 
is the bismuth trivalent, and what is the combining value 
of the bismuth in the other ? 

9. Write the empiric formula of H 2 2 . 

10. Write the empiric formula for H 2 2 4 . 

11. Write the molecular formula for the phosphate of 
triad iron. 

12. Write the molecular formula for barium phosphate. 

13. Write the molecular formulas for : (a) hypochlorous 
acid; (b) chlorous acid; (c) chloric acid; (d) perchloric acid ; 
(e) sodium bromate; (f) potassium periodate; (g) hyposul- 
phurous acid; (h) sulphuric acid; (i) sulphurous acid; (j) 
magnesium sulphite; (k) ferrous sulphate; (1) mercuric 
sulphate; (m) mercurous sulphate; (n) mercuric oxide; (o) 
sulphurous oxide; (p) hyponitrous acid; (q) nitrous acid; 



124 A CORRESPONDENCE COURSE IN PHARMACY 

(r) nitric acid ; (s) hypophosphite of magnesium ; (t) ferrous 
hypophosphite ; (u) ferric hypophosphite; (v) phosphoric 
oxide; (w) carbonic chloride; (x) ammonium phosphate. 

14. What is the difference between sulphuric sulphur, 
sulphurous sulphur and hyposulphurous sulphur ? 

15. What is the difference between nitric nitrogen, nitrous 
nitrogen and hyponitrous nitrogen ? 

16. What is the difference between hypochlorous chlorine, 
chlorous chlorine, chloric chlorine and perchloric chlorine ? 

17. What is the combining value of periodic iodine ? 

18. What is the algebraic combining value of phosphoric 
phosphorus ? 

19. What is the highest algebraic combining number 
possible to carbon, and what is carbon with its highest 
combining value called ? 

20. Give the technical name of 00 and of CQ 2 ? of H 4 0. 

21. What is the algebraic combining number of the acidic 
element in: (a) hypophosphorous acid; (b) calcium nitrate; 
(c) ferric sulphate; (d) ferrous sulphate; (e) sodium 
periodate ; (f ) potassium chlorate ; (g) potassium antimonite ; 
(h) sodium arsenate; (i) sodium hyposulphite; (j) sodium 
tetraborate; (k) pyrophosphate of iron; (1) orthophosphate 
of iron ; (m) metaphosphate of iron ; (n) any decaborate ? 

22. How many different kinds of phosphoric acids are 
possible, containing only one phosphorus atom ? 

23. How many different kinds of sulphuric acids are 
possible, containing only one sulphur atom? 

24. What kind of a meta-acid is H 2 B 4 7 ? 

25. Write the formula for normal nitric hydroxide. 

26. Write the formula for nitric mono-meta-hydroxide. 

27. Write the formula for nitric di-meta-hydroxide. 

28. Write the formula for normal sulphuric hydroxide. 

29. Write the formula for carbonic hydroxide of normal 
composition 



CHEMICAL NOMENCLATUBE 125 

30. Write the formula for mono-meta-carbonic hydroxide, 

31. What kind of a carbonate is Oa00 3 ? 

32. What kind of a carbonate would you call CaH 2 C0 4 ? 

33. What kind of a carbonate would you call KHC0 3 ? 

34. What kind of a carbonate is K 2 C0 3 ? 

35. Why are all the compounds just named called 
carbonates ? 

36. What is the difference between a chlorate and a 
perchlorate, and why are both called chlorates ? 

37. What is a thiosulphate and what is a hyposulphite ? 

38. Give the formula for thiocarbonic acid of normal 
structure. 

39. What would you call a compound of potassium oxygen 
and pentad iodine ? 

40. What would you call a salt containing carbon as its 
acidic element? 

41. What would you call a salt in which the acidic 
element is silicon? 

42. What would you call a salt in which the acidic element 
is tetrad sulphur ? 

43. What would you call a salt in which antimony with five 
bonds is the acidic element ? 

44. How many bonds does the nitrogen have in a 
hyponitrite ? 

45. How many different numbers of bonds can the nitrogen 
atom have in nitrates ? 

46. How many different numbers of bonds can the arsenic 
atom have in arsenites ? 

47. Write the formula for tri-meta-di-phosphoric acid. 

48. Write the formula for di-meta-phosphoric acid. 

49. If such a compound existed as penta-meta-tetra- 
phosphoric acid, what would be its formula ?' 

50. How many kinds of ferric hydroxide can exist contain- 
ing but one iron atom ? 



126 A CORRESPONDENCE COURSE IN PHARMACY 

51. Write the formula for tri-meta-di-ferric hydroxide. 

52. Write the formula for a salt containing hexad chromium 
as its acidic element. 

53. What is the difference between acidic manganic 
manganese and permanganic manganese ? 

54. Write the formula for potassium dichromate and state 
why it is called a dichromate. 



LESSON TEN 

XV 

The Relative Intensity of the Chemical Combining 
Energy of Different Elements 

225. Different elements possess widely different degrees of 
intensity of chemical energy, or tendency to combine with 
other elements or to attack other substances chemically. 

Among the strikingly energetic elements are fluorine, 
chlorine, bromine, phosphorus, potassium and sodium. 
Oxygen also may be said to show considerable inclination to 
enter into chemical combination, at least at temperatures 
somewhat above the common. 

Among the elements of comparatively indifferent chemical 
energy under ordinary conditions are carbon, silicon, boron, 
nitrogen, gold and platinum. 

Neon, argon, krypton and xenon show no inclination what- 
ever to enter into chemical combination. 

The properties of the element fluorine can be studied only 
with the greatest difficulty, if at all, because whenever that 
element is liberated from one of its compounds, it instantly 
attacks some other substance and forms some new chemical 
combination by uniting with some element in that other 
substance. 

Chlorine and bromine are also strikingly energetic in their 
chemical action upon other substances. 

Fluorine, chlorine and bromine decompose water and take 
the hydrogen away from it, setting the oxygen free. They 

127 



128 A CORRESPONDENCE COURSE IN PHARMACY 

also attack metals vigorously by combining with them. 
Fluorine attacks and decomposes glass. 

Phosphorus ignites and burns fiercely in oxygen and in 
chlorine and also combines with great velocity with bromine. 
It decomposes potassium chlorate with great violence. 

Potassium and sodium and, in still greater measure, caesium 
and rubidium, decompose water by combining with the 
oxygen of the water, or with its hydroxyl, and liberating 
hydrogen. The alkali metals must be preserved submerged 
in benzoin or some other liquid hydrocarbon (hydrocarbons 
contain only carbon and hydrogen), to prevent their instant 
and violent oxidation or combination with oxygen. 

Carbon is so indifferent chemically that diamond, graphite, 
coal and charcoal remain permanently unaltered in the 
presence of an abundance of oxygen, except when heated 
strongly. 

Crystallized silicon, adamantine boron and nitrogen are 
even more indifferent than carbon. But silicon and boron 
immediately ignite in fluorine gas, owing to the intense 
chemical energy of the latter. 

226. Elements differing widely from each other in their 
chemical quality show the greatest inclination to enter into 
combination with each other. Compounds formed by very 
energetic positive elements with very energetic negative ele- 
ments are stable; but compounds formed by elements 
exhibiting a low degree of intensity of chemical energy are 
comparatively unstable. 

The fluorides and chlorides of the alkali metals and alkaline 
earth metals are very stable compounds, because fluorine and 
chlorine are the most energetic of the decidedly negative 
elements and the alkaline earth metals are the most energetic 
of the decidedly positive elements. But most of the com- 
pounds formed by nitrogen show a remarkable tendency to 
decompose, often with explosive violence, because of the 



COMBINING ENEBGY OF DIFFEBENT ELEMENTS 129 

indifferent ability or inclination of nitrogen to hold other 
elements in combination with itself. 

227. Some acids are mnch more corrosive or destrnctive or 
energetic in their chemical action than other acids, and this 
difference does not depend npon their hydrogen or oxygen, 
since those elements belong to all true acids. But it 
must depend at least primarily upon the acidic element 
which characterizes the acid. Carbonic acid is H 2 C0 3 , or 
rather (HO) 2 CO. Sulphurous acid is H 2 S0 3 , or rather 
(HO) 2 SO. Sulphurous acid is a much more energetic acid 
than carbonic acid, and the difference between them is 
evidently due to the fact that the acidic element in one is 
sulphur, while in the other it is carbon. 

It is true that we have three kinds of hydroxyl acids in 
which sulphur is the acidic element, and that these three 
acids nevertheless differ greatly in their energetic action 
upon other substances. Sulphuric acid, H 2 S0 4 , is decidedly 
stronger than sulphurous acid, H 2 S0 3 , for sulphuric acid 
decomposes the salts of sulphurous acid and changes them 
into sulphates, while sulphurous acid does not decompose 
sulphates or change them into sulphites, and so sulphates 
are much more stable compounds than sulphites. Hypo- 
sulphurous acid, H 2 S0 2 , is weaker than either sulphuric or 
sulphurous acid. It may be said that the difference between 
these three acids, all containing sulphur as the acidic ele- 
ment, may be due not to that acidic element, since that is 
the same in all three, but to the differences in the proportion 
of oxygen, were it not for the fact that acids containing a 
larger proportion of oxygen are sometimes weaker acids than 
others that contain less oxygen. Boric acid, H 3 B0 3 , is a 
much more feeble acid than phosphorous acid, H 3 P0 3 , 
although the boric acid contains a larger proportion by 
weight of oxygen, the weight of the boron atom being only 
11, while that of the phosphorus atom is 31. Sulphuric 



130 A CORRESPONDENCE COURSE IN PHARMACY 

acid, H 2 S0 4 , is more destructive and energetic than chromic 
acid, H 2 Cr0 4 . 

An element performing the acidic function forms a stronger 
acid if it exercises a high combining value than the same 
element forms if it has a lower algebraic combining number. 
The sulphur in sulphuric acid is by no means identical in all 
respects with the sulphur in sulphurous acid, nor with the 
sulphur in hyposulphurous acid, for the chemical combining 
value of the sulphuric sulphur contained in sulphuric acid 
and all other sulphuric compounds is '+6; the chemical com- 
bining value of sulphurous sulphur contained in all sul- 
phurous compounds is 4-4, and that of hyposulphurous sulphur 
contained in all hyposulphurous compounds is only +2. 
This, then, explains the differences between sulphuric acid, 
sulphurous acid and hyposulphurous acid. 

228. Some alkaline hydroxides are more corrosive and 
destructive, or more decidedly alkaline or stronger, or 
chemically more energetic than others. This difference can- 
not be due to the oxygen and hydrogen, which are common 
to all of them; it must be due to the basic element in them. 
Potassium hydroxide is decidedly more powerful as a base 
than lithium hydroxide. This must be due to the difference 
between potassium and lithium. 

229. The relative intensity and power of different elements 
as chemical agents depend upon their polarity, valence, 
atomic weight, specific weight and their relative position in 
the natural system of classification of the elements known as 
the periodic system. 

It is also affected by physical conditions, as by solubility 
or want of solubility or different degrees of solubility of the 
compounds formed, or by their volatility or want of volatility. 

The apparent energy of one element is further decidedly 
influenced by the character and quantity of the element or 
elements with which it enters into combination* 



COMBINING ENERGY OF DIFFERENT ELEMENTS 131 

230. Elements capable of performing the basic function 
form more powerful bases if their specific weight is low; 
weaker bases if their specific weight is high. In other words, 
the light metals are strongly basic and the heavy metals 
less strongly basic. The hydroxides of most of the light 
metals are destructive, while the hydroxides of heavy metals 
are not so. 

231. Of the light metals, those having a low valence are 
more decidedly energetic in their chemical action and form 
stronger bases than those having a higher valence. It is 
equally true of the heavy metals that they are more strongly 
basic when of low valence than when exercising a high valence. 

Metals exercising a valence of more than 3 do not perform 
a basic function at all, but may instead perform the acidic 
function. 

232. Light metals belonging to the same natural family 
or group, and therefore having the same valence, differ from 
one another as to the intensity of their chemical energy, 
according to their atomic weights, those having the higher 
atomic weights being more energetic and more powerfully 
basic than those having smaller atomic weights. 

233. The hydroxides of all non-metallic elements are 
acids. In general, the hydroxyl acids formed by the non- 
metallic elements are more decidedly acid in their character 
the higher their algebraic combining number is, other things 
being equal. But non-volatile acids form more permanent 
salts than volatile acids, and more volatile acids form less 
permanent salts than less volatile acids. 

234. The halogens, fluorine, chlorine, bromine and iodine, 
when they exercise negative polarity or form fluorides, 
chlorides, bromides and iodides, exhibit an intensity of 
chemical energy in the inverse order of their atomic weights. 
The student should note that this behavior of the halogens 
is the very opposite of the behavior of the alkali metals. 



132 A CORRESPONDENCE COURSE IN PHARMACY 

Fluorine is the most energetic of the halogens, because it 
has the smallest atomic weight of all of them, while caesium 
is the most energetic of the alkali metals, because it has the 
largest atomic weight of all of those metals. 

But when chlorine, bromine and iodine perform the acidic 
function and accordingly exercise positive polarity, the 
stability of the salts they form is in the order of their atomic 
weights. Iodates are more permanent than bromates and 
chlorates, and the bromates are more permanent than the 
chlorates; the chlorides are more permanent than the bro- 
mides or iodides, and the bromides are more permanent than 
the iodides. 



XVI 

Chemical Reactions 

235. Chemical changes are called chemical reactions. 
They are rearrangements of the atomic linking in the mol- 
ecules of matter. 

The substances which take part in chemical reactions are 
called the factors, and the substances formed by the reaction 
are called the products. 

The factors may be two or more, but chemical changes 
sometimes take place in one single substance, so that we may 
have but one factor. 

The products are most frequently two, but there may be 
more than two, and there may be but one product. 

When two factors form one product, the reaction is called 
a synthesis. 

When one factor splits up into two or more products, we 
call the reaction dissociation. 

When two factors react upon each other and both of the 
factors are decomposed, with the result that two new products 



CHEMICAL REACTIONS 133 

are formed, the reaction is called a metathesis, or double 
decomposition. 

In any reaction where one element displaces another ele- 
ment in a compound factor, with the result that two products 
are formed, one of which is or contains the displaced ele- 
ment, we call the reaction substitution. 

The following examples will suffice to illustrate these several 
kinds of reactions : 

Fef2l=FeI 2 represents a synthetical reaction. 

CaC0 3 =CaO+C0 2 represents a dissociation. 

CaO+C0 2 =CaC0 3 represents a synthetical reaction. 

ZnO-f2HCl=ZnCl 2 +H 2 is an equation representing a 
metathesis. 

Zn+2HCl=ZnCl 2 +H 2 represents substitution. 

H 4 C+2C1=H 3 CC1+H01 is also a case of substitution. 

236. In order to explain the course of chemical reactions 
we shall find it convenient to use the term radical to indicate 
any atom or group of atoms transferred from one molecule 
to another, or liberated from a molecule, or entering into 
combination with another atom or group of atoms. 

A radical differs from a molecule in that the radical has 
unused combining power by means of which it can enter into 
combinations, while a molecule has all the combining power 
of its atoms fully occupied, so that the molecules do not 
enter into chemical combination in any manner dependent 
upon valence. 

The student has also learned that molecules may be divided 
into two ions —the positive ion and the negative ion. These 
ions are radicals. . In the molecule KC10 4 , K is the positive 
ion and the group C10 4 is the negative ion. K is the positive 
radical and C10 4 is the negative radical. 

237. Malaguti's Doctrine. Chemical reactions are subject 
to a tendency toward the pairing of the strongest radicals of 
opposite polarity. In other words, the strongest positive 



134 A CORRESPONDENCE COURSE IN PHARMACY 

radical present has a tendency to unite with the strongest 
negative radical present, because the strongest positive 
radicals form the most stable and permanent compounds 
with the strongest negative radicals, and it is self-evident 
that the tendency of all matter in the universe must be in 
the direction of the formation of molecules of the greatest 
degree of stability, or in other words, molecules best able to 
resist change. 

We have already observed that some acids are stronger 
than other acids, and that some bases are stronger than other 
bases. These facts depend upon the same tendency. The 
light metals are more strongly basic than the heavy metals, 
and the metals having a low valence are more strongly basic 
than those having a higher valence. Of any two metals 
having the same valence and belonging to the same natural 
family in accordance with the periodic system, the metal 
having the highest atomic weight is a stronger positive 
radical than another metal having a smaller atomic weight. 
Acidic elements having a higher algebraic combining number 
form stronger acids than the same elements when they 
exercise a lower algebraic combining number. 

238. But physical conditions affect chemical reactions very 
decidedly. The degree of solubility or of volatility of the 
products may nullify the tendency indicated by Malaguti s 
doctrine. Chemical reactions proceed more readily and 
more nearly to completion when one of the products is 
eliminated from the arena of chemical action as fast as formed 

239. Berthollet formulated the following doctrine : When- 
ever the formation of a volatile product is possible at the 
temperature at which the reaction occurs, then the course of 
the reaction will be determined accordingly, and that volatile 
product will be formed. The same proposition may be stated 
in this way: Chemical reactions are facilitated and rendered 
more complete when one or more of their products are gases. 



CHEMICAL EEACTIOKS 135 

Calcium carbonate can be decomposed by heat, because one 
of the products is the gas C0 2 . Ammonium chloride and 
calcium oxide heated together produce calcium chloride, 
water and ammonia, because the water and ammonia are 
volatile. Mercury sulphate and sodium chloride heated 
together form mercury chloride and sodium sulphate, if the 
temperature is high enough to vaporize the chloride of 
mercury. 

240. Another doctrine formulated by Berthollet is to the 
effect that whenever by any double decomposition between com- 
pounds in solution an insoluble or less soluble compound can 
be formed, then that insoluble or less soluble compound 
will be formed. An equivalent statement in different words 
is that chemical reactions between substances in a state of 
solution are facilitated and proceed to completion when one of 
the products is insoluble or only sparingly soluble in the liquid. 

If you know that phosphate of iron is insoluble in water, 
then you know also that you cannot mix a water-solution of 
any phosphate with a water-solution of any iron salt without 
getting a precipitate of phosphate of iron. A solution of 
acetate or nitrate of lead or any other soluble lead compound 
mixed with any solution of a sulphate will give a precipitate 
of lead sulphate, because lead sulphate is insoluble. The 
well known fact that calcium oxalate is insoluble tells us that 
if it is desired to remove the calcium from any solution, all 
that is necessary is to add a solution of some oxalate, because 
that would cause the formation of calcium oxalate, which 
would be precipitated. To know that the oxides, hydroxides, 
sulphites, carbonates, oxalates and phosphates of the heavy 
metals are all insoluble in water is to know that solutions of 
the water-soluble salts of those metals cannot be mixed with 
the solutions of any of the soluble hydroxides, sulphites, 
carbonates, oxalates or phosphates without producing pre- 
cipitates. 



136 A CORRESPONDENCE COURSE IN PHARMACY 

241. Malaguti's doctrine would lead us to the conclusion 
that when a mixture is made of a solution of sulphate of 
potassium and acetate of lead, no precipitate would be 
formed, and in fact no reaction would take place, because, of 
the two positive radicals, potassium and lead, potassium is 
the stronger, and of the two negative radicals, the sulphate 
radical and the acetate radical, the former is the stronger, 
and the tendency toward the union of the stronger positive 
radical with the stronger negative radical would prevent any 
change, because the potassium and the sulphate radical are 
already united. But a reaction does take place and sulphate 
of lead is formed, despite Malaguti's doctrine, because lead 
sulphate is insoluble. 

The tendency toward the formation of insoluble compounds 
by double decomposition always annuls or overcomes the 
tendency toward the pairing of the strongest positive and 
negative radicals, unless both tendencies operate in the same 
direction. 

242. From what has been said, it is evident that a good 
chemist must know the relative solubilities and volatilities 
of chemical compounds in order to be able to make a prog- 
nosis of chemical reactions. 

243. Substances in a solid state do not readily react upon 
each other. 

Gaseous substances react with each other more freely than 
solids, but less favorably than liquids. 

Substances in a liquid condition react most readily and 
completely, especially when held in solution by a liquid 
taking no part in the reaction. 

Solids react with liquids more readily than with other 
solids or with gases. 

Gases react readily with substances in a liquid condition. 

Substances which do not react upon each other at all in a 
dry condition may do so immediately upon being wetted. 



CHEMICAL KEACTIONS 137 

Solids which do not react upon each other at all at the 
ordinary temperature may react upon each other com- 
paratively freely when heated to the temperature at which 
they liquefy or the temperature at which one of the products 
formed by the reaction becomes liquid. 

244. Chemical Solution. Water-soluble salts and some 
other water-soluble compounds are generally produced by 
chemical solution ; that is, by the action of one factor in liquid 
form upon another factor in the solid or liquid or gaseous 
form. 

The solvents used are most commonly acids or alkalies, 
but occasionally solutions of salts. 

The acids or other chemical solvents are said to be neutral- 
ized or saturated by metals or metallic compounds dissolved 
in them. 

Acids are among the most common materials used in the 
laboratory for the production of other salts. 

Metals or their oxides, hydroxides or carbonates are 
dissolved in hydrogen chloride or so-called hydrochloric acid 
to produce metallic chlorides; in nitric acid to produce 
nitrates ; in sulphuric acid to make sulphates ; in acetic acid 
to produce acetates, and so on. This method is practicable 
whenever the products are water-soluble salts together with 
water, or water-soluble salts together with gaseous products, 
or both water and gas together with the salt. 

245. The Action of Heavy Metals upon the Common Acids. 
In common parlance, it is said that the acids attack certain 
metals, but it is clearly more consistent to say that the 
metals attack the acids, because while the metals are dissolved 
and turned into metallic compounds, they are not decom- 
posed, while it is strictly true that the metal causes the acid 
to decompose. 

Gold and the platinum metals do not attack any acid, but 
they dissolve in the mixture of nitric acid and hydrogen 



138 A CORRESPONDENCE COURSE IN PHARMACY 

chloride which is called nitro-hydrochloric acid, or aqua regia. 
Chlorides of gold and platinum are formed with the free 
chlorine contained in that mixture. 

Aluminum decomposes hydrochloric acid, forming alu- 
minum chloride and setting the hydrogen free. It does not 
attack other acids. 

Antimony is only physically a metal and therefore does not 
perform the basic function. Hence, when it decomposes 
nitric acid, it is simply oxidized to form insoluble antimonious 
oxide. Other acids are not affected by antimony. 

Tin decomposes strong nitric acid, forming what is called 
meta-stannic acid. It also decomposes hydrochloric acid, 
forming stannous chloride. Sulphuric acid is not decom- 
posed by tin. 

Bismuth quickly decomposes nitric acid, forming bismuth 
nitrate. It also attacks hot concentrated sulphuric acid, but 
not hydrochloric acid. 

Silver decomposes dilute nitric acid, forming silver nitrate. 
It also decomposes hot concentrated sulphuric acid, but it 
does not act upon hydrochloric acid. 

Lead dissolves in and decomposes nitric acid, forming lead 
nitrate, but it scarcely affects hydrochloric and sulphuric 
acid. 

Copper vigorously attacks nitric acid and also decomposes 
hot strong sulphuric acid, but it is not dissolved by hydro- 
chloric acid or diluted sulphuric acid. 

Nickel decomposes hydrochloric acid, sulphuric acid and 
nitric acid, forming nickelous salts. 

Iron and zinc readily decompose the diluted acids. 

246. Hydrochloric acid dissolves zinc, aluminum, iron, 
nickel and tin. It does not dissolve lead, copper, mercury, 
silver, gold, platinum, arsenic, antimony and bismuth. 

Diluted sulphuric acid dissolves zinc, iron and nickel, 
setting hydrogen free, but it does not dissolve aluminum, 



CHEMICAL REACTIONS 139 

lead, copper, mercury, silver, gold, platinum, tin, arsenic, 
antimony and bismuth. 

Concentrated sulphuric acid dissolves copper and, if hot, it 
is also attacked by mercury, silver and bismuth. 

When mercury, silver or bismuth attacks sulphuric acid, 
the products formed, in addition to the sulphates, are water 
and S0 2 . 

Moderately dilute nitric acid, especially when warm, 
dissolves zinc, iron, nickel, lead, copper, mercury, silver, 
arsenic and bismuth. Arsenic is oxidized to arsenic acid and 
the other metals form nitrates. So much of the nitric acid 
used as does not enter into the formation of the nitrate yields 
water and the gas NO, which . oxidizes in the air to red 
vapors of N 2 4 or N0 2 , or both, according to the temperature. 
It is commonly said that "red nitrous vapors" are formed 
when metals are dissolved in nitric acid. 

Gold and very dilute nitric acid dissolves iron and zinc, 
forming ferrous nitrate or zinc nitrate, together with 
ammonium nitrate and water. This fact is particularly 
interesting and instructive, for it will be seen that the 
ammonium nitrate can only be formed by changing the 
algebraic combining number of a part of the nitrogen from 
+5, which is the combining value it possesses as the acidic 
element of nitric acid, to —3, which is the combining value it 
has in any ammonium compound. This may most clearly 
be shown by the following equation: 4Zn+10HONO 2 =4Zn 
(N"0 8 ) 2 +H 4 NON0 2 +3H 2 0. The four zinc atoms before the 
metal is dissolved in the nitric acid have an algebraic com- 
bining number of 0. But in the four molecules of zinc 
nitrate which the metal forms, the zinc atoms have a total 
algebraic combining number of +8, for zinc in combination 
has a valence of 2. The four zinc atoms, therefore, gained 
eight units of combining value. The first nitrogen atom in 
the molecule H 4 NON0 2 , or the nitrogen of the ammonium, 



140 A CORRESPONDENCE COURSE IN PHARMACY 

has five bonds, four of which hold the four hydrogen atoms, 
while the fifth connects the H 4 N to the oxygen atom stand- 
ing between the two nitrogen atoms of the H 4 NON0 2 , and as 
the four bonds holding the hydrogen are negative bonds, 
while the fifth bond must be a positive bond, and as —4 added 
to +1 makes -3, the nitrogen atom of the H 4 N has a value 
of -3. Inasmuch as that nitrogen atom was furnished by 
the original HON0 2 , in which all the nitrogen has a value 
of +5, it follows that the nitrogen reduced lost eight units, 
for the difference between +5 and —3 is, of course, eight 
units. These eight units lost by the nitrogen atom are the 
eight units gained by the four zinc atoms. 

Concentrated nitric acid is not attacked by iron, but dis- 
solves lead, copper, mercury, silver, arsenic and bismuth. 
It is not affected by gold and platinum. It oxidizes tin to 
insoluble so-called meta-stannic acid, and antimony to insol- 
uble antimonious oxide. 

247. The foregoing statements must not be construed to 
mean that metals which are not dissolved by the acids named 
may not be superficially affected to a considerable degree. 

Diluted sulphuric acid does take up copper and form 
copper sulphate, so that copper vessels are corroded by diluted 
sulphuric acid. But the diluted acid dissolves the metal so 
slowly and to such a limited extent that we would not think 
of using diluted sulphuric acid for the purpose of dissolving 
copper. 

Tin is not affected by sulphuric acid, but tinned iron or 
"tin plate," however heavily coated with pure tin, is com- 
paratively soon destroyed by not only very dilute sulphuric 
acid, but even by boric acid solutions and by very weak acetic 
acid, probably because the tin coating is not so impervious 
that the iron is absolutely protected. 

248. Acids are readily attacked by metals if the salts 
formed by the reaction are soluble in the liquid. But metals 



CHEMICAL REACTIONS 141 

cannot be dissolved in the acids if the salts formed are 
insoluble in the liquid. Thus, strong nitric acid does not 
attack iron, because the iron nitrate is not soluble in strong 
nitric acid, but diluted nitric acid does attack iron, because 
the iron nitrate is soluble in diluted nitric acid and in water. 
Again, lead is not soluble in moderately diluted sulphuric 
acid, because lead sulphate is insoluble both in diluted sul- 
phuric acid and in water. But the lead is acted upon by 
concentrated sulphuric acid, because lead sulphate is soluble 
in that acid when of sufficient strength. 

249. Chemical reactions occurring in processes of manu- 
facture of chemical compounds are very generally of such 
character that the products formed are easily separable from 
each other. Were not this the case, they would be practically 
useless. 

A double decomposition resulting in the formation of one 
product soluble in the liquid in which the reaction takes 
place and another insoluble in that liquid is useful or 
practicable, because the insoluble substance is easily sepa- 
rated from the soluble. 

A reaction resulting in the formation of one product which 
is volatile and another which is not volatile is also workable, 
because the volatile product can be easily dissipated and 
separated from the non-volatile. 

Eeactions in which water is the only by-product are also 
useful, because water is volatile and can be eliminated, or, if 
the principal product is obtained dissolved in the water, it 
can be recovered from the solution by evaporation of the 
water and crystallization of the solid. 

Metallic salts are successfully made by the solution of the 
metal in the appropriate acid, because the by-product is 
either hydrogen or some other gas. Metallic salts are easily 
made from metallic oxides by dissolving these in acids, 
because the by-product is water. Salts can readily be made 



142 A CORRESPONDENCE COURSE IN PHARMACY 

by saturating acids with carbonates of the metals, because 
the by-products are water and the gas C0 2 . 

250. Neutralization is effected in solutions by mixing acids 
and alkalies, or acids and alkali carbonates, or acids and 
bases, etc., in the requisite proportions, adding either the 
acid to the metallic compound or the metallic compound to 
the acid. Acid salts are also neutralized by alkalies and 
alkali carbonates. 

Whenever practicable, the point of exact neutralization of 
an acid by a base or of a base by an acid is determined by a 
color reagent. The most common and useful reagent of this 
kind and for this purpose is litmus, which is generally 
employed in the form of litmus paper, which is unsized 
paper dipped in a solution of litmus and then dried. 

Litmus is a blue pigment which is very readily turned red 
by acids and blue by alkalies. Bine litmus paper is made 
from the unaltered solution of the pigment, while red litmus 
paper is made from a litmus solution to which just enough 
pure hydrochloric acid has been added barely to turn its color 
red. Litmus paper can also be made in such a way that it is 
neither red nor blue, by carefully adding just enough of the 
hydrochloric acid to the litmus solution used. 

A liquid which turns blue litmus paper red is said to have 
an acid reaction on test paper; one that turns red litmus 
paper blue is said to have an alkaline reaction upon test 
paper. A liquid which does not change the color of either 
red or blue litmus paper is said to have a neutral reaction 
on test paper, or to be neutral to test paper. The test is 
made by touching a small strip of the test paper with the 
liquid. 

251. Salts of normal structure formed by strong acids 
with weak bases have an acid reaction on test paper, but 
those formed by weak acids with strong bases have an 
alkaline reaction on test paper. Only salts formed by strong 



CHEMICAL REACTIONS 143 

acids with strong bases or weak acids with weak bases have a 
neutral reaction on test paper. 

Salts still containing some of the replaceable hydrogen of 
the acid are said to be acid salts, or to have an acid 
structure. Bicarbonate of potassium is such a salt, but 
bicarbonate of potassium, although of acid structure, has an 
alkaline reaction on test paper, because potassium is one of 
the most powerful basic elements, while the carbonate 
radical is a very feeble acid-radical. 

A salt containing a larger proportion of the basic element 
than that contained in a salt of normal structure is called a 
basic salt. Subsulphate of iron is such a salt, though a 
solution of subsulphate of iron has an acid reaction on test 
paper, because iron is not sufficiently strongly basic to form 
salts of neutral reaction with such a powerful acid as 
sulphuric acid. A solution of alum has an acid reaction, 
because aluminum is very feebly basic, although alum aiso 
contains potassium. 

252. When acids are saturated with the metal or with 
metallic oxides, hydroxides or carbonates, the proportions 
of these materials employed are determined beforehand 
according to the atomic and molecular weights, even if an 
excess of the metal or metallic compound is to be used. 
When salts of normal composition are to be prepared and the 
reaction on test paper does not indicate the composition, the 
exact theoretical proportions are used. 

When iron or zinc is dissolved in sulphuric acid, the metal 
is added in excess, because the acid cannot possibly dissolve 
any more of the metal than the quantity required to form 
the sulphate. But when mercury is dissolved in nitric acid, 
it is necessary that the proportions of mercury and nitric acid 
be carefully attended to, because if the nitric acid is in large 
excess, mercuric nitrate is formed, while with a less propor- 
tion of nitric acid, mercurous nitrate of normal structure is 



144 A CORRESPONDENCE COURSE IN PHARMACY 

formed, and with a still smaller amount of nitric acid, a basic 
mercurous nitrate is obtained. 

253. The proportions to be employed of the factors of a 
chemical reaction are, of course, indicated by the molecular 
weights and atomic weights. In constructing a working 
formula, it is therefore necessary first to write down the 
chemical equation that represents the reaction taking place 
in the process, and when this equation is properly balanced, 
the atomic or molecular weights will show the quantities 
required of the factors, and also the quantities obtained of 
the products. But the proportions found in this way are 
only the theoretical proportions, and they may not be work- 
able, because it is generally the case that the reaction is not 
complete under those conditions. 

If it is necessary that one of the factors in a chemical 
reaction be completely decomposed or consumed, then the 
other factor or factors must be used in greater proportion 
than that required by theory. 

If a double decomposition between A and B is to be effected, 
A must be used in excess over the theoretical proportion, if 
it is necessary that B shall be completely decomposed; if A 
must be completely decomposed, then B must be used in 
excess. 

In other words, the course and relative completeness of 
chemical reactions may be materially affected by the relative 
masses of the factors. 

When a solution of sodium sulphate and a solution of barium 
acetate are mixed in the proportions required for even or 
complete metathesis, barium sulphate and sodium acetate 
will be formed, and the reaction proceeds to completion, 
because the barium sulphate is insoluble. But if barium 
sulphate is placed in water containing a large amount of 
sodium carbonate in solution, the sodium carbonate will 
gradually decompose . the barium sulphate so that sodium 



CHEMICAL REACTIONS 145 

sulphate and barium carbonate are formed, and the insoluble 
solid matter in the liquid will become a mixture of barium 
carbonate and barium sulphate. If the sodium salts, which 
are soluble, are removed from time to time and fresh portions 
of sodium carbonate added, the entire amount of barium 
sulphate can be finally converted into bariuin carbonate. 
Mass reactions of this kind are numerous. 

254. The most common and numerous chemical reactions 
are double decompositions, and, as already shown, double 
decompositions are most readily effected between reagents in 
a state of solution, under Berthollet's law with regard to the 
formation of insoluble or less soluble products. In other 
words, they are precipitations. 

Other common reactions between acids and bases are also 
double decompositions. 

The student should therefore learn to write chemical 
reactions representing double decompositions. He should 
bear in mind that any double decomposition between two 
substances is simply a mutual interchange of radicals. It is 
like an exchange of partners in a quadrille ; two couples meet 
and exchange partners. Each factor in a chemical reaction 
such as is called double decomposition is a couple, consisting 
of the positive radical and the negative radical. The positive 
radical of one factor gives up its negative radical to the 
positive radical of the other factor and takes the negative 
radical from that factor in exchange. For example, sil- 
ver nitrate meets sodium chloride. The silver and the 
sodium are the positive radicals, the nitrate radical (N0 3 ) 
and the chlorine are the negative radicals. The silver 
gives up its N0 3 to the sodium, taking the chlorine in 
exchange. 

This double interchange may also be likened to an exchange 
of horses between two riders. A red man on a white horse 
and a white man on a red horse meet, and the two men 



14G A CORRESPONDENCE COURSE IN PHARMACY 

exchange horses. Both men are still there and so are the 
horses, hut they have changed positions. That is precisely 
what takes place between the several radicals concerned in a 
double composition. 

When mercuric chloride and potassium iodide, both in 
solution in water, are mixed with each other, the mercury 
leaves the chlorine and takes up the iodine instead, while 
the potassium, giving up the iodine to the mercury, takes 
up the chlorine in exchange. We started with a combina- 
tion of mercury and chlorine and a combination of potassium 
and iodine; we finish with a combination of mercury and 
iodine and a combination of potassium and chlorine. 

The equation representing the reaction is as follows: 
HgCl 2 +2KI=HgI 2 +2KCl. 

The reason why two molecules of KI are necessary is that 
the mercury atom has a valence of 2, whereas the atoms of 
chlorine, potassium and iodine each have a valence of only 1, 
and as we must have the same number of positive bonds as 
of negative bonds in any molecule, it follows that a molecule 
of mercuric chloride must contain two chlorine atoms to the 
one mercury atom, and a molecule of mercuric iodide must 
contain two iodine atoms to the one mercury atom. The 
two chlorine atoms contained in HgCl 2 require two potassium 
atoms to form potassium chloride, and two molecules of KI 
are required to furnish those two potassium atoms for the 
potassium chloride, as well as to furnish the two iodine 
atoms for the mercuric iodide. 

The easiest rule to follow is this: Find the valence of the 
positive radicals of the two factors^ and then tahe the number 
of atoms or molecules of each that . will give you a common 
multiple of the numbers expressing those valences. 

For example, if the valence of one of the positive radicals 
concerned is 1 and the valence of the other positive radical 
is 2, then multiply the factor containing the radical having 



CHEMICAL EEACTIONS 147 

a valence of 1 by 2, and multiply by 1 that factor the positive 
radical of which has a valence of 2. If the valence of the 
positive radical of one factor is 2 and that of the other is 3, 
then multiply the 2 by 3 and the 3 by 2. 

In the reaction represented by the equation ]N"a 2 C0 3 +CaCl 2 = 
CaC0 3 +2NaCl, the student will see that the positive radicals 
are the Na and the Ca. The valence of ISTa is 1 and the 
valence of Ca is 2, but as the Na is multiplied by 2 already 
and since the formula of the sodium carbonate is Na 2 C0 3 , 
one molecule of Na 2 C0 3 is sufficient, for the two sodium 
atoms together form two bonds, and the single calcium atom 
having a valence of 2 has also two bonds. 

The fact which the student should keep clearly in view is 
that the total number of bonds of the positive radical of one 
of the factors must be the same as the total number of bonds 
of the positive radical of the other factor. In order that the 
exchange may be even, it takes two five-dollar bills to match 
five two-dollar bills. 



Test Questions 

The number of questions in this and some of the following lessons may 
seem too great. Theoretically, it would be better if the lessons were 
more uniform in length, but as the real purpose of the Course is to 
insure a thorough understanding on the part of the student, the 
number of questions bears a close relation to the importance of the 
subject. 

It is not necessary that long answers should be written nor that 
all answers should be expressed in complete sentences. Occasionally 
"yes" or "no" may serve as an answer. Still, every answer must be 
clear and precise. 

If numerical computations are necessary, it is always desirable 
that the entire work of the problem should be submitted. If merely 
the answer is given and it is wrong, the instructor has no clue as to 
what is really the reason for the student's mistakes and so no assist- 
ance can be rendered. 



148 A CORRESPONDENCE COURSE IN PHARMACY 

1. What is meant by the factors of chemical reactions ? 

2. How many factors are necessary in a chemical reaction ? 

3. How many products are formed by any chemical 
reaction ? 

4. What is meant by dissociation ? 

5. How many factors are concerned in metathesis ? 

6. How many factors are necessary in a synthesis? 

7. What general expression is used to signify an alteration 
in the atomic linking of any molecule or molecules ? 

8. What is the difference between an elemental factor and 
a compound factor ? 

9. What is the algebraic combining value of an elemental 
factor in a chemical reaction ? 

10. When two elements enter into direct combination with 
each other, what is the algebraic combining number of each 
before the reaction and after the reaction ? 

11. What is meant by substitution ? 

12. What would you call a reaction in which two factors 
form but one product ? 

13. What would you call a reaction in which one factor 
furnishes two or three products ? 

14. What is the technical term used to designate a reaction 
in which two factors form two products without any change 
in the algebraic combining numbers of any of the ions ? 

15. Write a chemical equation representing a dissociation 
reaction. 

16. Write a chemical equation representing a synthesis. 

17. Write a chemical equation representing a substitution 
reaction. 

18. Write a chemical equation representing a double 
decomposition. 

19. What is the difference between a radical and an ion ? 

20. What is the difference between a radical and a 
molecule ? 



CHEMICAL REACTIONS 149 

21. What radicals are contained in sodium nitrate ? 

22. Write symbolic formulas representing the radicals con- 
tained in ammonium sulphate. 

23. By what means is it possible to determine which of 
several positive radicals is the most powerful and which of 
several negative radicals is most powerful, in order to predict 
the result of a chemical reaction under Malaguti's law ? 

24. Under what circumstances will the strongest positive 
radical unite with the weakest negative radical present in a 
reaction ? 

25. Under what circumstances will the results of a 
metathesis be the direct opposite of those indicated by 
Malaguti's doctrine ? 

26. State the laws of Berthollet governing the direction of 
metathetical reactions. 

27. What happens if you mix a solution of the sulphate 
of a heavy metal with a solution of phosphate of sodium ? 

28. What chemical change, if any, will take place when 
you mix a solution of ferric chloride with a solution of 
sodium hydroxide ? 

29. What chemical change, if any, will take place if you 
mix a solution of ferric chloride with a solution of sodium 
chloride ? Give the reason for your answer. 

30. Why will zinc oxide be obtained when zinc carbonate 
is strongly heated ? What else is formed at the same time ? 
Why does this reaction take place and what is it called ? 

31. What reaction, if any, will take place when you mix 
a solution of sodium phosphate with a solution of sodium 
carbonate ? Give the reason for your answer. 

32. What reaction will take place when you mix two 
bromides with each other ? 

33. What reaction will take place when you mix several 
potassium salts with one another ? Give the reason for your 
answer. 



150 A CORRESPONDENCE COURSE IN PHARMACY 

34. Will any chemical change take place when you mix a 
solution of potassium permanganate with a solution of 
potassium sulphite? If so, why, and what products are 
possible ? 

35. "Write the formula for oxalate of barium and state 
how it can be made by double decomposition. 

36. Lead iodide being insoluble, how would you make it ? 

37. What materials are necessary for the preparation of 
lead phosphate ? 

38. If you mix a solution of zinc sulphate with a solution 
of sodium oxalate, what reaction will take place, if any? 
State the products formed and what class the reaction 
belongs to. 



LESSON ELEVEN 

XVII 

Changes of the Algebraic Combining Numbers 
of Atoms 

255. Starting out with the assumption that the total 
algebraic sum of the positive and negative combining units 
or bonds of all atoms, free or combined, of all matter is 
at all times 0, we are led to the conclusion that when- 
ever the algebraic combining number of any atom is in- 
creased the algebraic combining number of some other atom 
or atoms must necessarily be diminished in exact proportion, 
and vice versa. 

If one atom gains one unit of combining value, that unit 
must be lost by some other atom. If any atom loses one 
unit, some other atom must gain it. If any atom gains two 
or more units of combining value, it must have received them 
from one or more other atoms. 

256. Units of combining value can be transferred from 
one atom to another, but their total cannot be added to nor 
diminished. 

Whether this proposition be called a chemical law or a 
mere mathematical device, it is extremely valuable and may 
be employed as an infallible rule. It serves to clear up 
many puzzling problems in chemistry, and gives a direct 
answer to many questions which cannot be readily solved 
without it. 

257. The term oxidation in its narrowest sense means 

151 



152 A CORRESPONDENCE COURSE IN PHARMACY 

combination with oxygen. But when HgCl 2 is converted 
into HgO by double decomposition, 

HgCl 2 +2KOH=2KCl+HgO+H 2 0, 

this change is not oxidation, although the Hg gives up its CI 
and enters into combination with instead. 

It is also frequently stated that oxidation includes any case 
in which any compound already containing oxygen is changed 
into another compound containing a greater proportion of 
oxygen. But this is not always true. 

When Na 2 S0 3 S is mixed with H 2 S0 4 the products formed 
are Na 2 S0 4 +S+S0 2 +H 2 0. The Na 2 S0 3 S contains a smaller 
percentage of oxygen than either Na 2 S0 4 or S0 2 ; but no one 
would say that Na 2 S0 3 S has been oxidized to Na 2 S0 4 or to 
S0 2 . We see instead that the Na 2 S0 3 S has been reduced 
to S0 2 . 

When Na 2 S0 3 in water solution is boiled with S the prod- 
uct formed is Na 2 S 2 3 . The Na 2 S0 3 contains 48 parts of 
oxygen in 126, while the Na 2 S 2 3 (or Na 2 S0 3 $) contains only 
48 parts of oxygen in 158 parts. The proportion of oxygen, 
therefore, is smaller in Na 2 S0 3 S than in Na 2 S0 3 ; but the 
Na 2 S0 3 is oxidized to Na 2 S 2 3 , for the sulphur atom added 
performs the same use in the structure of the Na 2 S0 3 as one 
of the oxygen atoms in the analogous compound Na 2 S0 4 . 

The change of S0 3 to H 2 S0 4 by means of H 2 0, 
S0 3 +H 2 0=H 2 S0 4 , 

is not called oxidation, although the percentage as well as the 
number of atoms of oxygen is greater in H 2 S0 4 than in S0 3 . 
The removal of hydrogen from an organic substance is 
commonly called oxidation; but such a change may be 
effected without reference to oxygen and in cases where no 
oxygen is contained in any of the compounds concerned. 
The substitution of chlorine or any other negative element in 
the place of hydrogen in any organic compound is oxidation 



CHANGES OF ALGEBRAIC COMBINING NUMBERS OF ATOMS 153 

of the atom which exchanges hydrogen for chlorine. But 
if another positive element or atom takes the place of 
the hydrogen united to any carbon atom in any organic 
compound, that carbon atom is not oxidized. If the group 
OH takes the place of a hydrogen atom in a hydrocarbon the 
change is oxidation, but the conversion of alcohol into ether, 

2C 2 H 5 OH=(C 2 H 5 ) 2 0+H 2 0, 

is neither oxidation nor reduction. 

The conversion of FeCl 2 into FeCl 3 is generally admitted 
to be oxidation, or is called oxidation of the FeCl 2 to FeCl 3 , 
and yet no oxygen is concerned in it unless the laborious 
explanation (sometimes given) is accepted that the change 
can take place only in water ; that the chlorine decomposes 
the water, taking the hydrogen from it to form hydrogen 
chloride ; that the oxygen of the water thus decomposed by 
the chlorine combines with the Fe of the FeCl 2 and the 
chlorine of that FeCl 2 combines with other hydrogen from 
water, and the oxide of iron and hydrogen chloride thus 
formed produce FeCJ 3 and H 2 0, thus: 



and 



2FeCl 2 +2Cl+3H 2 0=Fe 2 3 +6HCl, 



Fe 2 3 +6HCl=2FeCl 3 +3H 2 0. 



It does not seem to be necessary to discuss the question of 
the possible steps by which the FeCl 3 is formed. These 
steps are not demonstrable. But the reaction represented 
by the simple equation FeCl 2 +Cl=FeCl 3 is clear and intel- 
ligible and perfectly analogous to the reaction HgI+I=HgI 2 , 
which is as truly a case of oxidation as the other and which 
does not require the presence of any other substance. 

258. Reduction is generally defined as the opposite of 
oxidation. 

The removal of oxygen from any compound is nearly 
always truly reduction. In the sense in which the writer of 



154 A CORRESPONDENCE COURSE IN" PHARMACY 

this book, in common with many others, would use the 
term oxidation, the removal of one of the oxygen atoms from 
HO OH is not reduction, because the atom removed is the one 
having an algebraic combining number of 0, so that not one 
of the atoms of the HOOH undergoes any change of value. 
The transformation of FeCl 3 into FeCl 2 by means of zinc, 

2FeCl 3 +Zn==ZnCl 2 +2FeCl 2 , 

is generally admitted to be a reduction, and we say that the 
zinc acts as a reducing agent and reduces the FeCl 3 to 
FeCl 2 . But no oxygen is here concerned. 

We also speak of reducing Hgl 2 to Hgl by triturating the 
Hgl 2 with mercury : 

HgI 2 +Hg=2HgL 

When CaO is placed in contact with HC1 we obtain CaCl 2 
and H 2 0: 

CaO+2HCl=CaCl 2 +H 2 0, 
but no chemist would speak of this reaction as reduction, 
although the Ca is deprived of its oxygen. 

259. The manner in which the term oxidation is now used 
indicates that the original restricted meaning of the term is 
no longer adhered to. In its broadest sense that term now 
means an increase of the algebraic combining number of any 
atom. 

The use of the word "oxidation" in this broad sense is 
objectionable on the ground that it is derived from the word 
oxygen and should, therefore, not be applied to signify 
changes with which oxygen has nothing to do, and on the 
further ground that many chemists still employ the term in 
its original sense. Nevertheless, the need of some term to 
denote an increase in the true combining value of an atom, 
or a partial or complete change of the chemical polarity of an 
atom from negative to positive, or any other kind of aug- 
mentation of its algebraic combining number, is so urgent 



CHANGES OF ALGEBRAIC COMBINING NUMBERS OF ATOMS 155 

that the word oxidation has been employed for want of a 
better term, and no other single word has been suggested or 
used for that purpose. 

The whole subject of changes in the algebraic combining 
numbers of atoms is of so great importance that every 
student of chemistry must learn the fundamental facts con- 
cerning it before he can form any intelligent idea of some of 
the most common phenomena of chemical change. 

260. Eeduction, in its broadest sense, means a diminution 
of the algebraic combining number of any atom. 

261. Oxidation and reduction, understood in accordance 
with their broader application as stated in paragraphs 258 
and 259, must of course occur together. There can be no 
oxidation without corresponding reduction and no reduction 
without corresponding oxidation. 

262. An oxidizing agent is any atom having an algebraic 
combining number which is capable of being reduced. 

But the most useful and effective oxidizing agents are, of 
course, those atoms which most readily suffer a diminution 
of their algebraic combining value, and those whose algebraic 
combining number is so high that it may be reduced several 
units. 

Free chlorine is an effective oxidizing agent because of the 
great intensity of the chemical energy with which it forms 
chlorides with other elements or radicals. The algebraic 
combining number of free or uncombined chlorine is 0. 
When it forms chlorides its combining number falls to — 1. 
Hence each atom of chlorine furnishes only one unit of 
oxidation, for its algebraic combining number is diminished 
by only one unit. But it is nevertheless a powerful oxidizing 
agent, because it acts so readily. 

The combined chlorine in KC10 3 is also an effective 
oxidizing agent, and in this case its tendency to form, a 
chloride is not the only motive force which makes it a 



156 A CORRESPONDENCE COURSE IN PHARMACY 

powerful oxidizing agent, for the chlorine of KC10 3 has a 
high algebraic combining number (+5) which can be reduced 
six units (to —1), so that, while one atom of free chlorine can 
furnish only one unit of oxidation, the one atom of chlorine 
in one molecule of KC10 3 furnishes six units of oxidation. 

We say that nitric acid, HN0 3 , is a powerful oxidizing 
agent because it is easily decomposed and reduced to the 
compound NO. Two molecules of HN0 3 are said to give 
one molecule of water, two molecules of NO and three atoms 
of oxygen, 

2HN0 3 =H 2 0+2NO+30, 

and the liberated oxygen is said to effect the oxidation. 
But we can also and more simply explain the power of nitric 
acid to increase the algebraic combining number of atoms by 
the statement that it is the nitrogen atom of the HN0 3 
which is the real oxidizing agent; that nitrogen has a value 
of +5 in the HN0 3 and of only +2 in NO ; each molecule of 
HN0 3 accordingly furnishes 3 units of oxidation. 

Chromic anhydride, Cr0 3 , is a powerful oxidizing substance 
because the Cr in it has the high combining value of +6, 
which can be easily reduced to +3. Potassium dichromate, 
K 2 Cr 2 7 , contains two chromium atoms, each of which has a 
value of +6 capable of reduction to +3. Potassium per- 
manganate, KMn0 4 , contains an atom of manganese having 
a value of +7 capable of reduction to +2, so that one molecule 
of KMn0 4 furnishes five units of oxidation. 

263. Probably the strongest reasons for applying the term 
"oxidation" to any increase in the true combining value of 
any atom are these: 

Oxygen is the most abundant of all oxidizing agents. It 
is inexhaustible. 

Many of the most powerful oxidizing substances are oxygen 
compounds, and they may be said to act, at least indirectly, 
by giving up all or a part of their oxygen. 



CHANGES OP ALGEBEAIC COMBINING NUMBERS OF ATOMS 157 

Owing to the fact that nearly all elements can unite with 
oxygen, that oxygen compounds are so numerous, and that 
elements attain their highest algebraic combining values only 
in direct combination with oxygen, it follows that an extremely 
large proportion of the observed cases of augmentation of 
atomic combining value (oxidation in the broadest sense) are 
coincident with oxidation in the most restricted sense of 
that term. 

Even oxidizing agents that do not contain any oxygen may 
be seen to have derived their oxidizing power (an algebraic 
combining number capable of reduction) directly or indirectly 
from oxygen. For example, chlorine in the free state is 
obtained through the action of Mn0 2 , the Mn of which owes 
its high combining value (+4) to the oxygen with which it is 
combined. When the chlorine is liberated from HC1 by 
reaction with Mn0 2 , 

Mn0 2 +4HCl=MnCl 2 +2H 2 0+2Cl, 

it will be seen th§t the value of the Mn falls from +4 to +2, 
and that two atoms of chlorine, therefore, change their 
value from —1 to 0. 

Oxidations in which oxygen is not concerned are perfectly 
analogous' to those in which combination with oxygen takes 
place or in which the proportion of oxygen in an oxygen 
compound is increased. 

264. That there are strong reasons for using the term 
oxidation in its broader sense may be seen from the follow- 
ing examples: 

1. Iodine is the oxidizing agent in the reaction, 
6K0H+6I=5KI+KI0 3 +3H 2 0. 

All of the iodine had a combining value of 0. After the 
reaction five iodine atoms are seen to have each a value of —1, 
while the sixth iodine atom has a value of +5. 

KI0 3 is a powerful oxidizing agent. If this be ascribed to 



158 A CORRESPONDENCE COURSE IN PHARMACY 

its oxygen, then the KOH which supplied all of this oxygen 
may well be regarded as also an oxidizing agent ; and KOH 
in turn received its oxygen from some other source. But 
no chemist would say that KOH is an oxidizing agent. All 
chemists agree that iodine is an oxidizing agent and also that 
KI0 3 is one. The explanation most frequently made why 
iodine acts as if it were an oxidizing agent is that it decom- 
poses water, combining with the hydrogen of that water, 
whereby its oxygen is liberated so that it — the oxygen — is 
the real oxidizing agent. To render this clear we should 
have to represent the chemical changes as follows : 

5H 2 O+10I=10HI+5O. 

10KOH+10HI=10KI+10H 2 O. 

2KOH+2I+50=25IO s +H a O. . 

But KIO3 cannot be made directly out of KOH and I 
and 0. 

A more direct and satisfactory explanation is that five 
iodine atoms lose one unit each and form 5KI, while the 
sixth iodine atom gains the five units lost by the other five 
and forms KI0 3 . 

One-sixth of the iodine acts here as a reducing agent, 
being oxidized. 

2. Chlorine is the oxidizing agent in 

6Ca(OH) 3 +12Cl=50aCl 2 +Oa(C10 3 ) 2 +H 2 0. 
This is seen from the fact that 10 atoms of chlorine 
changed their algebraic combining number from to —1, 
thus losing together 10 units; these 10 units were taken up 
by the other two chlorine atoms, which each acquired a value 
of +5 in the Ca(C10 3 ) 2 . The Ca(OH) 2 is said to be oxidized 
to Ca(C10 3 ) 2 . Two atoms of CI were oxidized; ten of them 
were reduced. 

3. Sulphur is the oxidizing agent in 

Na 2 S0 3 +S=Na 2 S0 3 S. 



CHANGES OF ALGEBKAIC COMBINING NUMBEKS OF ATOMS 159 

The S in the Na 2 S0 3 evidently has a combining value of 
+4. The free S has a value of 0. But one of the atoms of 
S in the Na 2 S0 3 S has a value of -t-6, while the other has a 
value of -2. Hence, the S of the Na 2 S0 3 gained two units 
at the expense of the free sulphur. 

The Na 2 S0 3 is said to be oxidized to ]STa 2 S0 3 S. 

4. Phosphorus is the oxidizing agent in this reaction : 

3Ca(OH) 2 +8P+6H 2 0=3Ca(PH 2 2 ) 2 +2H 3 P. 

The student can readily see that while the P used had a 
value of 0, the P in the Ca(PH 2 2 ) 2 must have a value of +1, 
for the three calcium atoms have each a value of +2, the 
twelve hydrogen atoms have each a value of +1, and the 
twelve oxygen atoms have each a value of —2, so that the six 
phosphorus atoms must have a value of +1 each, for if we 
add +6, +12, -24 and +6 we get the sum of 0. Therefore 6 
atoms of phosphorus gained together six units, the total 
algebraic combining number of all of them being +6. The 
other two phosphorus atoms lost those six units, because the 
P in each molecule of H 3 P must have a value of —3. Hence, 
2 atoms of P acted as oxidizing agents and the other 6 
atoms of P as the reducing agents. 

5. Ten sulphur atoms are reduced and the two other 
sulphur atoms oxidized in 

3Ca(OH) 2 +12S=CaS0 3 S+2CaSS 4 +3H 2 0. 

The first sulphur atom in CaS0 3 S has a value of +6, and 
that is also the value of the first sulphur atom in CaSS 4 . 
All the other sulphur atoms have each a value of -2. 

6. In the following reaction, 
3Mn0 2 +12H01+6FeS0 4 =2Fe 2 (S0 4 ) 3 -f-2FeCl 3 +3MnCl 2 +6H 2 0, 

we can see that the three manganese atoms were reduced 
from a value of +4 to one of +2 each. The six atoms of iron 
(Fe) changed their value from +2 to +3. That this is clearly 
a case of oxidation is admitted by all chemists; but it is 



160 A CORRESPONDENCE COURSE IN PHARMACY 

difficult to explain why it is so if oxidation is combination 
with oxygen or an increase in the proportion of oxygen. It 
is true that the percentage of oxygen in Fe 2 (S0 4 ) 3 is greater 
than it is in FeS0 4 ; but the same is true of the percentage 
of sulphur. The whole truth is that the proportion of S0 4 
is greater in Fe 2 (S0 4 ) 3 than in FeS0 4 . We see that the Mn 
exchanged its two oxygen atoms for two chlorine atoms, and 
that change is truly reduction. But to say that this reaction 
is an oxidation because the H of the HC1 takes the oxygen of 
the Mn0 2 to form H 2 is a very unsatisfactory explanation. 

The statement of fact that the three manganese atoms 
together lose six units and that the six iron atoms gain those 
six units is a more direct and satisfactory explanation. 

The student is requested to observe that when a strong 
acid acts on Mn0 2 the algebraic combining number of the 
manganese is forced down to +2. Compare this result with 
that shown in the next example. 

7. In the equation, 

3Mn0 2 +2KOH=K 2 Mn0 4 +Mn 2 3 +H 2 0, 

one manganese atom rises from a value of +4 to one of +6, 
while the other two manganese atoms fall from +4 to +3 each. 
The presentation of the strong alkali KOH to the man- 
ganese in the Mn0 2 forces its value up from +4 to +6 in order 
that K 2 Mn0 4 may be formed. Compare this result with 
that in the preceding example. 

8. No one will deny that the H 2 S0 3 is oxidized to H 2 S0 4 
and that the FeCl 3 is reduced to FeCl 2 in 

2FeCl 3 +H 2 S0 3 fH 2 0=2FeCl 2 +H 2 S0 4 +2HCl. 

But we do not say that the water is the oxidizing agent, 
although it does supply the oxygen atom which changes the 
H 2 S0 3 to H 2 S0 4 . To say that one-third of the chlorine of 
the 2FeCl 3 splits off from it, leaving 2FeCl 2 , and that the 
CI thus set free decomposes the H 2 0, taking the hydrogen 



CHANGES OF ALGEBRAIC COMBINING NUMBERS OF ATOMS 161 

from it to form the 2HC1, while the oxygen atom of the H 2 
performs the oxidation of the H 2 S0 3 to H 2 S0 4 , is a labored 
explanation. The most direct and satisfactory explanation 
lies in the evident fact that the two iron atoms of the 2Fe01 3 
lost two units and- the S of the H 2 S0 3 gained those two units 
of combining value. 

9. In the reaction, 

4Zn+10HNO 3 =4Zn(NO 3 ) 2 +H 4 NONO 2 +6H 2 O, 
the nitric acid certainly acts as an oxidizing agent, but only 
one molecule of it performs that function, for the other 
eight molecules form the zinc nitrate and the ammonium 
nitrate. The first N in the H 4 NON0 2 has a combining 
value of —3, while the second N in that molecule and all the 
nitrogen in the 4Zn(N0 3 ) 2 has a value of +5, which is also the 
value of all the N in the HN0 3 . The one N which fell from 
+5 to —3 lost 8 units. What became of them ? They went 
to the four zinc atoms, which have a value of in the free 
state but of +2 in Zn(N0 3 ) 2 . 

10. In the reaction H 4 NON0 2 =2H 2 0+N' 2 we can see that 
the nitrate is reduced to N 2 0, but how ? The first N in the 
H 4 NON0 2 has a value of -3 ; the second has a value of +5. 
The nitrogen atoms in N 2 have each a value of +1. There- 
fore, one nitrogen atom gained 4 as it rose from —3 to +1, 
while the other lost 4 units as it fell from +5 to +1. 

The difference between the valence and the algebraic 
combining number is strikingly shown in the foregoing, for 
each nitrogen atom in H 4 NON0 2 has 5 bonds or a valence of 
5, while one has an algebraic combining number of —3 (the 
sum of —4 and -f 1) and the other has five positive bonds or 
an algebraic combining number of +5. 

11. In H 4 NONO=2H 2 0+2N, we see that the first N" in the 
H 4 ¥ONO has an algebraic combining number of -3 and the 
second of +3. As both of these atoms were liberated, one 
gained 3 and the other lost 3. 



1G2 A CORRESPONDENCE COURSE IN PHARMACY 

12. In the reaction, 

2HgCl 2 +S0 2 +2H 2 0=2HgCl+2HCl+H 2 S0 4 , 
it is of course possible to explain that two chlorine atoms of 
the 2HgCl 2 decomposed one molecule of water, forming 
2HC1, and that the liberated oxygen formed one molecule of 
H 2 S0 4 by combining with the S0 2 and the second molecule 
of water, but we prefer to say that the two mercury atoms 
lost two units of algebraic combining value which were both 
gained by the S of the S0 2 , thus rendering the formation of 
H 2 S0 4 possible. 

13. In the reaction, 

Cu+2H 2 S0 4 =CuS0 4 +S0 2 +2H 2 0, 
we might explain that the copper replaced the two hydrogen 
atoms of one of the molecules of the H 2 S0 4 and that these 
two hydrogen atoms combined with one of the oxygen atoms 
of the other molecule of H 2 S0 4 , reducing it to H 2 S0 3 , after 
which this H 2 S0 3 split up into S0 2 and H 2 0. But as we 
know that hydrogen does not reduce H 2 S0 4 to H 2 S0 3 or 
decompose it in any way, we prefer to say that the copper 
gained two units and that the S of one of the molecules of 
H 2 S0 4 lost those units and therefore formed S0 2 . 

265. Any atom having a low algebraic combining number 
capable of augmentation is a possible reducing agent. But 
an effective and convenient reducing agent is an atom which 
may be easily oxidized, and especially one which can have its 
algebraic combining number increased by several units. 

Any true metal acts as a reducing agent whenever it enters 
into chemical combination with any element whatsoever, 
because a free element has an algebraic combining number 
of and all metals in combination are positive. 

Chlorine, whenever it forms KC10 3 , or even KCIO, is a 
reducing agent, because that chlorine is itself oxidized, just 
as carbon forms either C0 2 or CO when used to reduce 
metallic oxides and certain other oxygen compounds. 



CHANGES OF ALGEBRAIC COMBINING NUMBERS OF ATOMS 163 

Hydrogen sulphide is a reducing agent because the sulphur 
of the H 2 S has the low value of —2, which can be raised to 0, 
or to +2, or +4, or even to +6. Ammonia is a reducing 
agent because its nitrogen has a value of —3, capable of being 
raised to +5. 

S0 2 is a reducing agent because its S can have its value 
increased from +4 to +6. 

Test Questions 

1. What is meant by the term algebraic combining 
number ? 

2. What is the algebraic combining number of metallic 
silver ? 

3. What is the algebraic combining number of chlorine ? 

4. What is the algebraic combining number of silver 
chloride ? 

5. In the reaction H+C1=HC1, what are the algebraic 
combining numbers of the H, the CI and the HC1 ? 

6. What are the algebraic combining numbers of the Na in 
NaCI, the Ag in AgCl, the Na in NaN0 3 and the Ag in 
AgN0 3 , and what are the algebraic combining numbers of 
NaCl, AgCl, NaN0 3 and AgN0 3 ? 

7. When H 2 2 is dissociated into H 2 and 0, is that change 
an oxidation or a reduction ? Give the reason for your 
answer. ■ 

8. Can the potassium of any potassium compound act as 
an oxidizing agent or as a reducing agent ? 

9. Can the silver of any silver compound act as an oxidiz- 
ing agent or a reducing agent ? If so, explain how. 

10. Can sulphuric acid act as an oxidizing agent, and if 
so, how ? What element in the sulphuric acid is reduced ? 

11. Why is permanganate of potassium so powerful an 
oxidizing agent ? 



164 A CORRESPONDENCE COURSE IN PHARMACY 

12. Why is potassium chlorate an effective oxidizing 
agent ? 

13. Why is Mn0 2 useful as an oxidizing agent ? 

14. What is formed when free sulphur acts as an oxidizing 
agent ? 

15. What is formed when free chlorine acts as an oxidizing 
agent ? 

16. What is formed when free phosphorus acts as a reduc- 
ing agent ? 

17. Identify the oxidizing agent and the reducing agent 
in the equation: 3Mn0 2 +2KOH=K 2 Mn0 4 +Mn 2 3 +H 2 0. 

18. Identify the oxidizing element and the reducing ele- 
ment in the following reactions : 

(a) 3P+5HN0 3 +2H 2 0=3H 3 P0 4 +5NO. 

(b) 6Sb+10HNO 3 =Sb 2 O 5 +5H 2 O+10NO. 

(c) 3H 2 S+8HN0 3 =3H 2 S0 4 +4H 2 0+8NO. 

(d) 3Hg+8HN0 8 =3Hg(NO,) a +4H a O+2NO. 

(e) 3Hg+4HN0 3 =3HgN0 3 +2H 2 0+NO. 

(f) 3Hg+3H 2 S0 4 +2HN0 3 =3HgS0 4 +4H 2 0+2NO. 

(g) S0 2 +2HN0 3 =H 2 S0 4 +2N0 2 . 
(h) HN0 3 +8H=H 3 N+3H 2 0. 

(i) HN0 8 +3HCl=NOCl+2H a O+2Cl. 

(j) 3MnO 2 +KC10 3 +6K0H=3K 2 Mn0 4 +KCl+3H 2 O. 

(k) 2MnO a +KC10 8 +2KOH=2KMn0 4 +KCl+H 2 0. 

(1) 2HgCl 2 +S0 2 +2H 2 0=2HgCl+H 2 S0 4 +2HCl. 

(m) C 2 H 5 0H+2C1=C 2 H 4 0+2HC1. 

(n) H 4 NN0 3 =2H 2 0+N 2 0. 

(o) H 4 NN0 2 =2H 2 0+2N. 



LESSON TWELVE 

XVIII 

The Periodic System 

>. It has been found that the elements when arranged 
in certain periods according to their atomic weights 
naturally fall into groups, the members of which exhibit 
striking similarities of chemical behavior. This has been 
expressed as follows: "The chemical properties ,of the 
elements are periodic functions of their atomic weights"; 
and this statement is called the periodic law. 

When the periodic system was first presented in the form in 
which we now state it, several of the now known elements 
had not yet been discovered. Nevertheless, the evidences of 
the' fact of the periodicity of the regularities and similari- 
ties of valence and functions in accordance with the atomic 
weights were so overwhelming as to command attention 
immediately, and subsequent discoveries have confirmed the 
belief that the natural classification of the elements in 
accordance with this system is based upon natural law. 

267. If the seven elements beginning with lithium and 
ending with fluorine, arranged in accordance with their 
increasing atomic weights, be set down in succession, we will 
have : 

Li Be B C 1ST F 
7 9 11 12 14 16 19 

The elements are indicated by their symbols, and the 
numbers are their atomic weights. There are no known ele- 

165 



166 A CORRESPONDENCE COURSE IN PHARMACY 

ments having atomic weights between 7 and 19 except those 
mentioned in this period of seven. Lithium, the first mem- 
ber of the period, is an alkali metal and the last is a halogen. 
The striking result of this arrangement is that the ruling 
valences of these seven elements in the order in which they 
stand are 1, 2, 3, 4, 3, 2 and 1. The element having the 
next higher atomic weight above 19 was sodium, with the 
atomic weight of 23, which is also an alkali metal, like 
lithium. 

If we now set down another period of seven elements in 
the order of their atomic weights, beginning with sodium, we 
shall have 

Na Mg Al Si P S CI 
23 24.2 27 28.4 31 32 35.4 

No other elements with atomic weights between 19 and 36 
are known. The seventh element is again a halogen, and the 
respective ruling valences of the elements in the order in 
which they are set down are again 1, 2, 3, 4, 3, 2 and 1. 

But the ruling valences of elements are not their only 
important valences. If the polarity as well as the valence be 
considered in connection with this second period of elements, 
and the maximum algebraic combining numbers be given 
instead of the ruling valences, the result is even more strik- 
ing, for the maximum algebraic combining numbers of these 
seven elements, beginning with Na, in the order in which 
they stand, are +1, +2, +3, +4, +5, +6 and +7. 

The element next following chlorine in the order of increas- 
ing atomic weight is again an alkali metal, namely, potassium. 
If we now set down the seven elements, beginning with 
potassium, in the order of their atomic weights, we get: 

K Ca Sc Ti V Cr Mn 
39 40 44 48 51.5 52 55 

In this period we find that the last element, manganese, 



THE PERIODIC SYSTEM 167 

is not a halogen, but the maximum algebraic combining 
numbers of these seven elements are again, as before, +1, 
+2, +3, +4, +5, +6 and +7. (The student will remember 
that the halogens are fluorine, chlorine, bromine and iodine. ) 
We have seen that two periods of seven elements, beginning 
with alkali metals, end with the halogens fluorine and 
chlorine. If we now set down bromine at the right and put 
down in front of it the six elements standing next to bromine 
in the order of their decreasing atomic weights, we get the 
following result : 

Cu Zn Ga Ge As Se Br 
63.5 65.3 70 72.5 75 79 80 

Three elements are known having atomic weights between 
55 and 63.5; namely, iron, nickel and cobalt. We have 
therefore a break here in the regular periodicity before noted. 
The maximum algebraic combining numbers of the elements 
from copper to bromine are +2, +2, +3, +4, +5, +6 and +5, so 
that in this period the first and the last elements do not 
appear to follow the same rule as before. Copper sometimes 
has the algebraic combining number +1, but no compound of 
bromine is known in which that element has a combining 
value as high as +7. 

If we now set down another period of six, beginning with 
the alkali metal rubidium, which stands next after bromine 
in the magnitude of its atomic weight, we have : 

Rb Sr Yt Zr Cb Mo 
85.5 87.5 89 90.5 93.5 96 

The seventh element belonging to this period is evidently 
not yet known, for these six elements are closely related to 
K, Ca, Sc, Ti, V and Or, and they have the combining values 
1, 2, 3, 4, 5 and 6. 

The next period may be made to begin at the right with 



168 A CORRESPONDENCE COURSE IN PHARMACY 

the halogen iodine. Going backwards from iodine to silver, 
we get this result : 

Ag Cd In Sn Sb Te I 

108 112 114 119 120 125.5 126.5 

In that period of seven elements, the maximum algebraic 
combining numbers are unmistakably +1„ +2, +3, -+4, -4-5, +6 
and +7. 

Evidently such results as these cannot be accidental. The 
reasons for the irregularities and exceptions to be observed 
in arranging the chemical elements in accordance with this 
system will doubtless some day be discovered. 

268. Several tables have been arranged on this plan, and 
of these the most useful to the beginner will be found on 
page 171. At the top of the table are the maximum algebraic 
combining numbers, and in the last four columns below 
the maximum combining numbers the student will find the 
minimum algebraic combining numbers. All of the elements 
in the first column are alkali metals, and no alkali metals are 
found in any other column. In the second column or group 
are the alkaline earth metals. In the last column are all of 
the halogens, and in the next to the last column we find oxygen 
and the sulphur family, which are also closely related to 
each other. Indeed, throughout the whole table it will be 
found that the members of any group or family of elements 
placed in a vertical column possess certain similarities and 
exhibit certain gradations in differences which cannot be 
accidental. 

Any element in the table will be found to possess properties 
intermediate between the properties of its neighbors on both 
sides, or above and below. 

Some of the elements belonging in the vacant spaces in 
the table from the middle down are really known, though a 
little uncertainty exists in regard to their atomic weights. 



THE PERIODIC SYSTEM 169 

At least six elements are known having atomic weights 
between 139 and 173. Some day these vacant places in the 
table will probably be filled with the elements that belong 
there but that have not yet been discovered. 

269. At the time Professor Mendeleeff constructed his first 
periodic table, the element scandium was unknown, also the 
elements gallium and germanium, but their discovery and 
leading properties and atomic weights were predicted by 
Mendeleeff, and within three years they were discovered and 
his predictions found to be true. He knew that scandium, 
with an atomic weight of about 44, must exist; calcium had 
a valence of 2 and titanium a valence of 4, so that an ele- 
ment with a valence of 3 must belong between them, and, 
moreover, the difference between the atomic weights 40 and 
48 was too large. 

Gallium and germanium were believed to belong between 
zinc and arsenic, because zinc had a valence of 2 and arsenic 
a maximum algebraic combining number of +5, so that 
one element with a value of 3 and another with a value 
of 4 ought to exist having atomic weights between 65.3 
and 75. Gallium and germanium fulfilled these require- 
ments. 

At the time of the construction of Mendeleeff's first table, 
the atomic weight 120 had been assigned to uranium, whereas 
antimony had that same atomic weight. Moreover, uranium 
could not belong in the same family with antimony and does 
not possess a combining value of 5, so that Mendeleeff 
declared that the atomic weight of uranium was probably not 
120. It was subsequently shown that uranium had the 
atomic weight 240, which places it in the sixth group, 
where it properly belongs according to its combining 
value. 

• 270. Some other striking facts brought out in the periodic 
table are as follows : 



170 A CORRESPONDENCE COURSE IN PHARMACY 

The range of combining values of all elements in the last 
four columns, so far as they have variable valences, is always 
eight units. The highest algebraic combining number of 
carbon and all the other elements in the same family is +4, 
and the lowest algebraic combining number, —4. In the 
next column, the highest value is +5 and the lowest —3. In 
the oxygen and sulphur group, the highest value is +6 and 
the lowest —2, and in the last column, the highest value 
is +7 and the lowest -1. 

It will also be found that any element standing to the 
right, when in chemical combination with any element to 
the left, has a constant combining value, and also that any 
element standing abo7e, when in chemical combination with 
any element standing below it, has a constant combining 
value. Thus, when chlorine is in combination with either 
sulphur, phosphorus or silicon, or any metal, the chlorine 
has a constant algebraic combining value of —1, but when 
chlorine is in combination with fluorine or with oxygen, it 
may have a combining value of +1, +3, +5 or +7. Sulphur, 
in combination with any element to the left, invariably has 
the . combining value —2. But when in combination with 
oxygen or with any of the elements in the last column, it 
may have a combining value of +2, +4 or +6. 

This fact may be stated in the following manner: Any 
atom in combination with another element has invariably the 
same algebraic combining number, if that combining number 
is a minus quantity. Thus, a single boron atom, whenever 
in combination with hydrogen or with any element standing 
to the left in the periodic table, always has a combining value 
of —3. A single carbon atom, in combination with any ele- 
ment or elements standing below it or to the left of it in the 
periodic table, can have no other combining value except —4. 
A single nitrogen atom, whenever it has a combining number 
represented by a minus quantity, has the algebraic combining 



THE PERIODIC SYSTEM 



171 



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172 A CORRESPONDENCE COURSE IN PHARMACY 

number —3, and sulphur always has the combining value —2 
whenever it is negative. 

In other words, the relative polarities of any two elements 
in combination depend upon their relative positions in the 
periodic system. In the table here given, it will be seen 
that all the metals, together with hydrogen, are found in the 
first thirteen columns of the table, and that the non-metallic 
elements are all to be found in the upper right-hand corner 
of the table. 

271. There are probably no elements having atomic weights 
between 9 and 11 and between 27 and 28.4. But lithium 
and beryllium certainly belong in the first two columns, and 
sodium, magnesium and aluminum belong in the first three 
columns, whereas the non-metallic elements surely belong in 
the last columns of the table. For this reason the first 
two periods of elements have been separated, as shown, 
in order that the natural families of elements may be pre- 
served. 

272. Another striking fact is that in the first column of 
elements and in the second, the greatest energy, or inclina- 
tion to enter into chemical combination, is exhibited by 
those members having the highest atomic weights, all of 
these elements having positive polarity, whereas at the other 
end of the table, the elements having the lowest atomic 
weights exhibit the greatest energy if they exercise negative 
polarity. But when chlorine, bromine and iodine exercise 
positive polarity, iodine forms the most permanent com- 
pounds, bromine next and chlorine next. 

273. While it is true that our present chemical nomen- 
clature was devised long before the periodic system was 
known, we can readily see that with a few corrections, that 
nomenclature is in perfect accord with the periodic system. 
When any positive element has but two different combining 
values, its higher value is expressed by the ending ic and its 



THE PERIODIC SYSTEM 173 

lower value by the ending ous. When a positive element 
has three different combining values, the highest is generally 
expressed by the ending ic, the middle value by the ending 
ous, and the lowest value by the prefix hypo and the ending 
ous. When a positive element has four different combining 
values, the two middle values are indicated by the endings 
ous and ic, the lowest value by the prefix hypo and the end- 
ing ous, and the highest value by the prefix per and the end- 
ing ic. Thus carbonous carbon has a value of +2 and car- 
bonic carbon has a value of +4. Phosphoric phosphorus has 
a value of +5, phosphorous phosphorus a value of +3 and 
hypophosphorous phosphorus has a value of +1. Sulphuric 
sulphur has the combining value +6; the algebraic com- 
bining number of sulphurous sulphur is +4 and that of 
hyposulphurous sulphur must be +2. Perchloric chlorine 
has a value of +7, chloric chlorine a value of +5, chlorous 
chlorine a value of +3 and hypochlorous chlorine a value 
of+1. 

274. Four elements recently discovered in the atmosphere 
evidently belong next after the halogens. Neon, with the 
atomic weight 20, belongs between fluorine and sodium; 
argon, with an atomic weight of probably 39, belongs between 
chlorine and potassium; krypton, with an atomic weight of 
82, belongs between bromine and rubidium, and xenon, with 
an atomic weight of 128.5, belongs between iodine and 
caesium. Fluorine, chlorine, bromine and iodine as negative 
elements exhibit the most tremendous chemical energy, 
whereas sodium, potassium, rubidium and caesium are 
invariably positive elements, and as such exhibit the greatest 
energy shown by any elements of positive polarity. What, 
then, should be expected of neon, argon, krypton and xenon 
except a neutral behavior ? Standing between the extremely 
negative and the extremely positive elements, they exhibit 
no inclination to enter into combination at all. 



17*4 A CORRESPONDENCE COURSE IN PHARMACY 

Test Questions 

1. What is meant by the periodic system ? 

2. What is the maximum algebraic combining number 
possible to any element in the fifth place of a period of seven 
elements ? 

3. What is the lowest algebraic combining number possible 
to an element contained in the seventh place of a period of 
seven elements containing any elements of negative polarity ? 

4. Name the sixth element in the period beginning with 
potassium, and the third element in the period beginning 
with sodium. 

5. Name all the elements in the period beginning with 
copper. 

6. How is it possible to predict approximately the prop- 
erties of an undiscovered element ? 

7. What is the algebraic combining number of phosphorus 
in combination with any metal ? 

8. What is the algebraic combining number of sulphur in 
combination with any element standing below it or above it 
in the table of the periodic system ? 

9. What is the algebraic combining number of sulphur 
when in combination with oxygen or with any of the elements 
in the vertical column to the right of that in which the sul- 
phur is placed ? 

10. What position in the periodic table is occupied by the 
two elements of invariably negative polarity ? 

11. What position in the periodic table is occupied by 
elements combining directly with both hydrogen and oxygen ? 

12. What elements form no compounds with either hydro- 
gen or oxygen, and what position in the periodic table do 
they occupy ? 

13. What position in the periodic table is occupied by 
elements that combine with oxygen but not with hydrogen ? 

14. What elements form no compounds with oxygen ? 



THE PERIODIC SYSTEM 175 

15. What position is occupied in the periodic table by- 
elements that form no compounds with any of the halogens 
nor any compounds with any metal ? 

16. What are the relative positions of the most decidedly 
positive and the most decidedly negative elements in the 
periodic table as presented in this chapter ? 

17. Which is the positive element and which the nega- 
tive element in any compound consisting of bromine and 
chlorine ? 

18. Which is the positive element and which the negative 
element in any compound consisting of sulphur and 
tellurium ? Why ? 

19. If potassium is brought in contact with a mixture of 
bromine and iodine and the amount of potassium is sufficient 
to combine with only one of them, what compound will be 
formed ? 

20. If bromine be added to a solution of chloride of 
potassium, what new binary compound will be formed, if 
any? 

21. If bromine is added to a solution of iodide of potas- 
sium, what new binary compound will be formed, if any ? 

22. If 39.2 grams of potassium and 23 grams of sodium be 
put in a vessel containing 8 grams of pure oxygen, what will 
be formed and why ? 

23. Which is the more powerful basic element, caesium 
or barium ? 

24. Which is the more powerful basic element, barium or 
calcium ? 

25. Which is the more powerful negative element, chlorine 
or bromine ? 

26. What elements form no chlorides as shown by the 
periodic table ? 

27. What elements form no oxides as shown by the periodic 
table ? 



176 A CORRESPONDENCE COURSE IN PHARMACY 

28. Name the several elements with which positive 
sulphur can be in direct combination. 

29. Name the several elements with which positive iodine 
can be in direct combination. 

30. What binary compounds of bromine are not bromides ? 

31. What binary compounds of sulphur are not sulphides ? 

32. What binary compounds of carbon are not carbides ? 

33. What would you call a compound of boron and 
hydrogen ? - - 

34. What would you call a compound of boron and 
nitrogen ? 

35. What would you call a compound of calcium and 
carbon ? 

36. What would you call any binary compound formed by 
a metal with a non-metallic element ? 

37. What would you call a substance composed of two 
metals ? 

38. What is the probable reason why neon, argon, krypton 
and xenon form no chemical compounds ? 



LESSON THIRTEEN 
XIX 

Air and "Water — Nitrogen, Oxygen and Hydrogen 

275. Air is a mixture consisting almost wholly of the two 
colorless, odorless and tasteless gaseous elements called 
nitrogen and oxygen. 

Each five liters of air contains about four liters of nitrogen 
and one of oxygen. 

One cubic-decimeter of pure dry air at 0° C. under 760 
mm. pressure weighs 1.29303 grams. One cubic decimeter of 
ordinary air at 16.67° 0. weighs about 1.2125 grams. 

276. Nitrogen may be obtained by burning phosphorus in 
air contained in a suitable closed vessel. The phosphorus 
takes up all the oxygen with which it enters into chemical 
combination, forming a white solid called phosphoric oxide, 
and the gas remaining in the vessel is the nitrogen, which is 
not combustible. Mtrogen can also be made in various 
other ways. 

It requires a pressure of 35 atmospheres at or below the 
temperature of -146° C. to liquefy nitrogen. 

One cubic-decimeter of pure nitrogen weighs about 
1.26 grams. 

Nitrogen does not readily enter into chemical combination 
with other elements. It is contained chemically combined 
with hydrogen, carbon and oxygen, in many animal sub- 
stances. Among the most familiar nitrogen compounds are 
niter (saltpeter), from which nitrogen derives its name, and 
ammonia. 

177 



178 A CORRESPONDENCE COURSE IN PHARMACY 

Many nitrogen compounds are powerful explosives, as 
nitroglycerin, guncotton, dynamite. 

Nitric acid is a compound formed by nitrogen with oxygen 
and hydrogen, and this acid is one of the most destructive 
in its effects upon many other substances. 

The substances called alkaloids, of which quinine, strych- 
nine and morphine are well-known examples, all contain 
nitrogen. 

The so-called "laughing gas" employed by dentists to ren- 
der the patient unconscious of pain in extracting teeth is a 
compound of nitrogen and oxygen. 

Nitrogen is quite harmless when inhaled, as we know from 
the fact that the air we breathe contains so large a propor- 
tion of it, and hyponitrous oxide is also harmless if pure and 
properly used. But many of the most fearful poisons 
known, as prussic acid (hydrocyanic acid), "cacodyl cyanide," 
toxines, strychnine and many other alkaloids, are nitrogen 
compounds. 

277. When nitrogen enters into chemical combination 
with hydrogen alone, one single atom of nitrogen holds not 
more and not less than three atoms of hydrogen. The 
compound thus formed is a colorless gas called ammonia, 
which is readily soluble in water. The water-solution of it 
is also called ammonia and is much employed. Ammonia 
gas is excessively pungenfc, irritating, stifling, and dangerous 
in its effects upon the eyes, respiratory organs, etc., and the 
solution or "ammonia water," unless very dilute, is also 
destructive. 

Ammonia has the power of neutralizing acids, and the 
compounds formed by such neutralization are called 
"ammonium salts." 

278. When nitrogen combines chemically with oxygen 
alone, one nitrogen atom can hold either one or two oxygen 
atoms, or two nitrogen atoms together can hold one or three 



AIR AND WATER— NITROGEN, OXYGEN AND HYDROGEN 179 

or five oxygen atoms in combination. Nitrogen, therefore, 
combines with oxygen in five different proportions. If we 
represent the nitrogen atom by its symbol N and the oxygen 
atom by 0, the oxides of nitrogen are pictured by the follow- 
ing molecular formulas : 

NO is a colorless gas composed of one atom of nitrogen 
and one of oxygen. It is nearly always produced when a 
metal acts chemically upon nitric acid, but as it comes in 
contact with the air it immediately combines with more 
oxygen, forming N0 2 or N 2 4 , or both, according to the 
temperature, and these constitute the well-known irritating 
"red nitrous vapors" observed when metals are dissolved in 
nitric acid and when that acid is decomposed by certain 
other substances. NO is commonly but erroneously called 
"nitric oxide"; its true scientific name is nitrosyl. 

N0 2 is a red vapor above 150° C, and is called nitrogen 
peroxide. It is also called nitryl. But N0 2 may be con- 
densed into an orange-colored liquid of the composition N 2 4 , 
which is called nitrogen tetroxide. 

N 2 is a colorless gas commonly called "nitrous oxide 
gas" or "laughing gas." Its true scientific name should be 
hyponitrous oxide. N 2 3 is a blue liquid. It is called 
"nitrogen trioxide," but its true scientific name should be 
nitrous oxide. It forms nitrous acid with water. 

N 2 5 is a white solid which forms nitric acid with water. 
It is called "nitrogen pentoxide." This is the only oxide of 
nitrogen that can be properly called nitric oxide. 

[The proper nomenclature of these nitrogen compounds 
will be explained later on in the chapter on chemical 
nomenclature.] 

279. Oxygen. The vast importance of oxygen may well 
be appreciated from the fact that it constitutes about one- 
half of the whole mass of the earth. 

All of the well-known elements except fluorine form 



180 A CORRESPONDENCE COURSE IN PHARMACY 

chemical compounds with oxygen, and the oxygen compounds 
are therefore the most numerous and abundant of all sub- 
stances, whether mineral, vegetable or animal. 

About one-fifth, by weight, of the air is oxygen. 

Water is composed of eight-ninths, by weight, of oxygen 
and one-ninth of hydrogen. 

The oxygen of the air is of vital importance to life. 
Animals inhale air and appropriate a part of its oxygen. 
They exhale the unused part of the oxygen together with 
the nitrogen and, with these, the carbon dioxide (C0 2 ) and 
water (H 2 0) formed in the process of oxidation, which is the 
important object of respiration. 

Oxygen is a colorless, odorless, tasteless, non-inflammable 
gas. It becomes liquid at —120° 0. under a pressure of 50 
atmospheres. 

One cubic-decimeter of pure oxygen at 0° C. under 760 mm. 
barometric pressure weighs about 1.43 grams. Hence, 1 gram 
of oxygen under the conditions stated occupies a volume of 
about 699 cubic-centimeters. 

Oxygen is commonly prepared by heating certain easily 
decomposed compounds containing it. The substances called 
potassium chlorate (KOC10 2 ), mercuric oxide (HgO), man- 
ganese dioxide (Mn0 2 ), barium dioxide (Ba0 2 ), and 
lead dioxide (Pb0 2 ), may be used for this purpose. Potas- 
sium chlorate gives up all of its oxygen when heated, 
about two grams of oxygen being obtained from every five 
grams of the chlorate, and the residue is potassium chlo- 
ride (KC1). 

280. Whenever one atom of oxygen enters into chemical 
combination with hydrogen alone the oxygen atom unites 
with two hydrogen atoms. We, therefore, conclude that 
the combining value of one oxygen atom is twice that of one 
hydrogen atom. 

No one atom of any other element can combine with more 



AIE AND WATER — NITROGEN, OXYGEN AND HYDROGEN 181 

than four oxygen atoms unless the compound contains more 
than two elements. 

At ordinary temperatures oxygen exhibits no great inclina- 
tion to enter rapidly into combination with other elements 
except with phosphorus and with the elements called the 
alkali metals; but many elements are oxidized at higher 
temperatures and many are slowly oxidized by oxygen at the 
common temperature. 

281. Ozone is a gas consisting of oxygen alone but differ- 
ing decidedly from ordinary oxygen, ozone being much more 
active in causing oxidation. The difference between ordinary 
oxygen and ozone is due to the fact that each individual 
particle of common oxygen (0 2 ) consists of only two atoms, 
while each individual particle of ozone consists of three 
atoms (0 3 ). 

282. Oxidation signifies, in the narrowest sense of the 
term, the chemical combination of any element with oxygen. 

Fire is a violent or rapid chemical process by which the 
burning substances, or one or more of their component ele- 
ments, enter into chemical combination with the oxygen of 
the air. This rapid oxidation is called combustion and pro- 
duces heat, the intensity of which is in direct proportion to 
the velocity of the oxidation and dependent also upon the 
kind and quantity of the fuel "consumed." The elements 
of greatest importance as fuel are carbon and hydrogen in 
combination with each other and with other elements, or 
carbon alone. When carbon undergoes combustion it 
combines with oxygen to form oxides of carbon. 

Eespiration is attended with "slow combustion," by which 
certain substances contained in the venous blood entering the 
lungs are " oxidized" by the oxygen of the air inspired into 
those organs, and this process is a heat-producing chemical 
action. 

Slow oxidation may be seen not only in the results of 



182 A CORRESPONDENCE COURSE IN" PHARMACY 

respiration but also in many other phenomena, as, for 
instance, in the tarnishing of iron and some other metals 
when exposed to moist air. 

283. Oxides. Any compound consisting of only two ele- 
ments, one of which is oxygen, is called an oxide. But a 
compound of a metal with oxygen is a salt if a part of the 
metal performs the basic function and another part the acidic 
function. 

Silver oxide is a compound of silver and oxygen ; the metal 
magnesium forms magnesium oxide; zinc forms zinc oxide. 

But some elements have more than one oxide. Carbon has 
two, phosphorus has three, chlorine four, nitrogen five, and 
manganese seven different oxides; for the elements named, 
and also many other elements, can combine with oxygen in 
more than one proportion. 

Whenever any oxide consists of but two elements, each 
individual particle or molecule of that oxide, if it contains 
more than four atoms of oxygen, must contain more than 
two atoms of the other element ; and two atoms of one kind 
may hold in combination or be directly united to one, two, 
three, four, five or seven atoms of oxygen. 

[Distinction may profitably be made between oxides 
composed of two elements in which all of the oxygen is 
directly combined with all of the other element, and the 
so-called oxides composed of two elements in which two 
oxygen atoms may" be directly combined with each other. 
In HOH the oxygen is all combined with all of the 
hydrogen; but in HOOH each oxygen atom is directly 
combined with only one of the two hydrogen atoms.] 

The oxides of the metals are all solids ; but those of the 
non-metallic elements are some of them solids, others 
liquids, and others gases. 

Many of the oxides can be produced by combustion, or by 
direct combination of oxygen with other elements. 



AIR AND WATER— NITROGEN, OXYGEN AND HYDROGEN 183 

284. Examples of Oxidation by Combustion, (a) Sulphur 
(S) burns with a blue flame, combining with the oxygen 
of the air to form that oxide of sulphur which constitutes 
the familiar, irritating, colorless gas produced when a 
sulphur match burns. No ash is formed. Each atom 
of the sulphur combines with two atoms of oxygen; hence 
the irritant sulphurous oxide is called a dioxide and it 
is represented by the symbolic formula S0 2 , in which S 
stands for one atom of sulphur and 2 for two atoms of 
oxygen. 

As one atom of sulphur weighs twice as much as one 
atom of oxygen, it follows that the sulphur dioxide obtained 
weighs twice as much as the quantity of sulphur "con- 
sumed." 

[Another oxide of sulphur exists which cannot be pro- 
duced by combustion. It is a white solid and it is a trioxide, 
the composition of which is clearly indicated by its symbolic 
molecular formula, S0 3 .] 

(b) When charcoal, which is nearly pure carbon (C), is 
ignited and "consumed" by fire, or undergoes combustion, 
the carbon is oxidized. But if the supply of air or oxygen 
is insufficient the carbon does not combine with the maxi- 
mum amount of oxygen it can hold in chemical combination, 
but with only one-half as much. A carbon utom weighs 12 
times as much as an atom of hydrogen; but an oxygen atom 
weighs 16 times as much as a hydrogen atom. The carbon 
oxide formed by incomplete combustion of the carbon is 
composed of 12 parts of carbon and 16 parts of oxygen and 
it is in fact carbon monoxide, or CO. The oxide formed 
when the carbon undergoes complete combustion is composed 
of 12 parts of carbon and 32 parts of oxygen, and is in fact 
carbon dioxide, or C0 2 . 

Both of the oxides of carbon are colorless gases. They 
are the only two oxides carbon can form. 



184 A CORRESPONDENCE COURSE IN PHARMACY 

Carbon monoxide is combustible. It burns in the air with 
a blue flame, taking up from the air as much more oxygen 
as it already contains, being thus oxidized to carbon dioxide. 
This oxidation is represented symbolically as follows: 

CO+0=C0 2 . 

But carbon dioxide is not combustible, because carbon can- 
not hold in combination with itself more than 2f times 
its own weight of oxygen, or, in other words, because one 
carbon atom cannot hold more than two oxygen atoms in 
direct combination if the compound contains no other 
element. 

When pure carbon is thus oxidized no ash is formed. 
Twelve kilograms of carbon consume for complete oxidation 
thirty-two kilograms of oxygen, producing forty-four kilo- 
grams of carbon dioxide. 

(c) Alcohol is composed of the three elements carbon, 
hydrogen and oxygen. When it is ignited and burns in a 
free supply of air the flame is smokeless, the combustion is 
complete, no ash or residue is left, and the products are 
carbon dioxide, C0 2 , and water, H 2 0. Each molecule of 
alcohol is composed of two atoms of carbon, six atoms of 
hydrogen and one atom of oxygen. Its molecular formula 
is, therefore, empirically written C 2 H 6 0. Hence, each mol- 
ecule of alcohol weighs 46 times as much as one hydrogen 
atom. Each molecule of alcohol requires 6 additional atoms 
of oxygen for the formation of two molecules of carbon 
dioxide and three molecules of water. Accordingly, the 
combustion of alcohol is represented by the chemical 
equation, 

C 2 H 6 0+60=2C0 2 +3H 2 0. 

Hence, 46 kilograms of alcohol will require 96 kilograms of 
oxygen for complete combustion and the products will be 88 
kilograms of carbon dioxide and 54 kilograms of water vapor. 



AIR AND WATER — NITROGEN, OXYGEN AND HYDROGEN 185 

(d) Wood is a complex mixture of organic substances com- 
posed mainly of carbon, hydrogen* and oxygen, but contain- 
ing also some compounds of potassium, calcium and other 
elements. When wood is used as fuel the products of the 
combustion are chiefly the oxides of carbon and hydrogen, 
which we have already mentioned. These pass off, together 
with some "unconsumed" carbon and other matter, as smoke, 
while the compounds of potassium, calcium, aluminum, 
silicon and other "mineral matters" contained in the wood 
form the ash. 

(e) When the soft white metal called magnesium (Mg) is 
ignited it burns rapidly, emitting an intense white light as it 
unites with the oxygen of the air to form a white solid, which 
is magnesium oxide, MgO. The "flash light" powder used 
by photographers consists of or contains powdered mag- 
nesium. 

No gas is formed in the combustion of magnesium, for the 
only product is the oxide, which is a fine powder, forming a 
cloud of white dust but no smoke. Thus the only product 
here is the ash. Five grams of this white ash is produced 
out of every three grams of the metal, because a mass of 
3 grams of magnesium unites with 2 grams of oxygen. 
Magnesium and oxygen unite with each other in no other 
proportions. Hence, we see that when magnesium is "con- 
sumed" by combustion it yields in fact a product weighing 
66 per cent more than the metal consumed. 

Magnesium oxide is commonly called "magnesia." 
(/) When the black mineral called antimonite, or "black 
sulphide of antimony," which is composed of the elements 
antimony (Sb) and sulphur (S), is strongly heated or 
"roasted" in the air it decomposes. As one molecule of the 
black sulphide of antimony is composed of 2 atoms of anti- 
mony and three atoms of sulphur its symbolic formula is 
written Sb 2 S 3 . The antimony is oxidized by the oxygen of 



186 A CORRESPONDENCE COURSE IN PHARMACY 

the air to antimony oxide, Sb 2 3 , which fuses and forms a 
glass-like solid, while the sulphur forms the gas S0 2 . As 
the atomic weight of antimony is 120, because any given 
number of atoms of antimony weigh 120 times as much as 
the same number of atoms of hydrogen, it follows that when 
336 grams of Sb 2 S 3 is completely oxidized to Sb 2 3 and S0 2 , 
the quantity of oxygen required must be 144 grams, and that 
the combustion or oxidation is represented by the equation, 

Sb 2 S 3 +90=Sb 2 3 +3S0 2 . 

From these examples the student will learn that fire or 
combustion does not change the amount of matter in the 
universe ; it simply alters the composition and form of matter 
by rearrangements of the atoms into other kinds of mol- 
ecules ; and that the weight of the product or products formed 
by a burning substance is greater than that of the substance 
burned by just the amount of oxygen taken up in combination 
to form the new substance or substances. 

285. Water is one of the most plentiful oxygen compounds 
in nature. It is a most wonderful substance, composed of 
two of nature's most remarkable elements, hydrogen (H) and 
oxygen (0). In each molecule, or smallest possible individual 
particle of water, there are two hydrogen atoms and one 
atom of oxygen. Its molecular formula is, therefore, written 
H 2 ; but it may also, and preferably, be represented by the 
formula HOH. 

Water forms solutions of numerous kinds of matter and is 
indispenable to circulation and nutrition in plants and 
animals, rendering possible the chemical processes without 
which life in the world of matter must cease. It is the 
most, neutral or chemically indifferent substance with regard 
to the vast majority of other kinds of matter, serving there- 
fore a3 a medium in which other substances may be liquefied, 
whereby their molecules acquire greater freedom of motion, 



AIR AND WATER — NITROGEN, OXYGEN AND HYDROGEN 187 

so that they can readily act upon each other. Its power to 
cause the dissociation of certain kinds of molecules into 
their component "ions" is referred to elsewhere. Molecules 
of water have a remarkable power and tendency to enter 
into some form of combination with other kinds of molecules, 
as "water of crystallization" and in other ways. Its uses 
in the economy of nature, in sanitation, and in the indus- 
tries of civilization could not be subserved by any other sub- 
stance known. 

Water freezes at 0° C. (32° F.). Its boiling point is 100° 
C. (212° F.). It attains its maximum density at 4° C. 
(39.2° F.). 

One liter of water at 4° C. in vacuo weighs 1 kilogram. 
One milliliter weighs 1 gram. 

Six pints of water (96 fluid ounces) weighs approximately 
100 avoirdupois ounces. 

286. Hydrogen is a colorless, odorless, tasteless, highly 
inflammable gas. It is the lightest of all kinds of matter, 
occupying nearly 14^- times as much space as is taken up by 
an equal weight of air, and about 11,160 times as much 
space as is occupied by an equal weight of water at 0° C. 

One cubic-decimeter of pure hydrogen at 0° 0., bar. 
760 mm., weighs about 0.09 gram. 

Hydrogen has been obtained in liquid form at a temper- 
ature estimated to be below —200° 0., and under a pressure 
of 40 atmospheres. 

This element exists in nature in the free state only in 
extremely small quantities. In chemical combination it 
constitutes about 1 per cent by weight of the whole mass of 
the earth. Its most abundant compound is water. Hydro- 
gen is a constituent of nearly all of the carbon compounds of 
the animal and vegetable kingdoms, and of coal oil, "natural 
gas" and other bituminous products. 

287. Hydrogen is easily prepared by the action of zinc on 



188 A CORRESPONDENCE COURSE IN" PHARMACY 

diluted sulphuric acid. Ordinary sulphuric acid is a hydrogen 
sulphate composed of two hydrogen atoms, one atom of sul- 
phur, and four oxygen atoms. Its molecular formula, repre- 
senting its composition, is best written (HO) 2 S0 2 . When 
zinc (Zn) is added to a solution of sulphuric acid (or " diluted 
sulphuric acid") the zinc takes the place of the hydrogen, 
forming zinc sulphate, and the hydrogen is set free : 
Zn+(HO) 2 S0 2 =Zn0 2 S0 2 +2H. 

Hydrogen can also be made by passing steam (water vapor) 
over coal heated to a very high temperature. Carbon mon- 
oxide (CO) is formed at the same time, the reaction being 
HOH+C=CO+2H. 

By the action of sodium hydroxide upon sodium formiate 
a perfectly pure hydrogen may be made : 

NaOH+NaCH0 2 =Na 2 C0 3 +2H. 

288. Chemically considered, hydrogen is extremely im- 
portant. Its properties place it between the metals and 
the non-metallic elements. It forms no true chemical com- 
pound with any true metal, but combines with all non- 
metallic elements. Its oxide or hydroxide, water, is neither 
a base nor an acid ; but if one of the hydrogen atoms of the 
molecule of water, HOH, be replaced by a non-metallic ele- 
ment an acid is the result, whereas if a metal (of low combining 
value or valence) is substituted for one of the hydrogen 
atoms a base is formed. Hydrogen is contained in all acids. 

Hydrogen does not at ordinary temperatures display any 
inclination to enter into chemical combination with other 
elements, but a mixture of hydrogen and chlorine, or of 
hydrogen and oxygen, may be exploded by an electric spark 
or by ignition. 

The most intense heat that can be produced by combustion 
is that produced by igniting a mixture of hydrogen and 
oxygen in the proportions required to form water. Practical 



AIR AND WATER — NITROGEN, OXYGEN AND HYDROGEN 189 

use is made of this in the "oxy-hydrogen blowpipe." By 
means of this, hydrogen burning in oxygen is thrown against 
a fragment of lime which quickly rises to an intense white 
heat and gives off the well-known powerful "lime light." 

No one atom of any kind can unite directly with (or hold 
in combination) more than four hydrogen atoms. 

Carbon and silicon can unite with four hydrogen atoms ; 
boron, nitrogen, phosphorus, arsenic and antimony each with 
three ; oxygen, sulphur, selenium and tellurium with two ; 
and fluorine, chlorine, bromine and iodine each with only 
one hydrogen atom. ISTo other elements unite directly with 
hydrogen under any circumstances. 

Hydrogen forms alloys with a few of the metals, notably 
palladium. 

Ammonia (H 3 N) is the compound formed when one nitro- 
gen atom is combined with all the hydrogen it can hold in 
combination. 

289. As hydrogen of all elements has the lowest atomic 
weight, and of all substances the lowest specific weight, and 
as it has a uniform atomic combining value or valence as 
low as that of any other element, it has been adopted as the 
standard of comparison and unit of expression of all such 
values. Thus the atomic weight of hydrogen is 1, its vapor 
density is 1, and its valence is 1. 

290. Hydrogen and oxygen are chemical opposites. 
Hydrogen is one of the positive elements ; oxygen is always 
a negative element. Any element is oxidized whenever it 
combines with oxygen; it is reduced whenever it combines 
with hydrogen. An element is reduced whenever its oxygen 
compound exchanges its oxygen for hydrogen. An element 
is oxidized whenever its hydrogen compound exchanges its 
hydrogen for oxygen. Any element is positive whenever it 
is in direct combination with oxygen ; it is negative when- 
ever it is in direct combination with hydrogen. 



190 A CORRESPONDENCE COURSE IK PHARMACY 

Test Questions 

1. What is the weight of one liter of pure dry air at 25° 
C. under the pressure of one atmosphere? 

2. Is air a chemical compound ? 

3. Is water a chemical compound ? 

4. Why are nitrogen compounds generally unstable ? 

5. What is the proper technical name of so-called "laugh- 
ing gas"? 

6. Name one common nitrogen compound having a 
decided odor. 

7. What is the algebraic combining number of nitrogen in 



9 



H 4 NC1 and in N 2 5 

8. Mention ten compounds containing oxygen. 

9. Can oxygen be obtained from air ? 

10. How is oxygen generally produced ? 

11. What is the difference between oxygen and ozone ? 

12. Name several examples of simple oxidation. 

13. What is the composition of calcium oxide? 

14. What is the composition of potassium oxide ? 

15. What is the composition of aluminum oxide ? 

16. What is the percentage of oxygen in S0 3 ? 

17. What are the products of the combustion of charcoal ? 

18. What are the products of the combustion of hydro- 
carbons ? 

19. What is the composition of the ash left on the com- 
bustion of magnesium ? 

20. How much antimonous oxide can be produced by 
roasting one kilogram of antimonous sulphide ? 

21. What is the algebraic combining number of the oxygen 
in water and what is it in "hydrogen dioxide" ? 

22. Is hydrogen dioxide really an oxide, or can you give 
a more scientific name for it? 

23. What is the importance of hydrogen oxide to plants 
and animals? 



AIE AND WATEE— NITROGEN, OXYGEN AND HYDROGEN 191 

24. What is meant by ionization ? 

25. How is hydrogen produced ? 

26. What products are formed when steam is passed over 
strongly heated coal ? 

27. Name four great classes of compounds containing 
hydrogen. 

28. If you remove one hydrogen atom from each of two 
molecules of water and put one atom of sulphur in their 
place, what will be the compound formed ? 

29. If you put one atom of sulphur in the place of four 
hydrogen atoms removed from four molecules of water, what 
will be the resulting compound ? 

30. If you put a nitrogen atom in the place of five 
hydrogen atoms removed from five molecules of water, what 
will be the resulting compound? 

31. If you put a sodium atom in the place of one hydrogen 
atom of a molecule of water, what will you have ? 

32. If you put a calcium atom in the place of two atoms 
of hydrogen removed from two molecules of water, what will 
be formed ? 

33. If you put one sulphur atom in the place of six 
hydrogen atoms taken from six molecules of water, what will 
be the compound formed ? 

34. If from that compound you remove two hydrogen 
atoms and one oxygen atom, what will remain ? 

35. If you remove from it four hydrogen atoms and two 
oxygen atoms, what will be the technical name of the 
residue ? 

36. If you take away three molecules of water from the 
compound formed by putting one sulphur atom in the place 
of six hydrogen atoms removed from six molecules of water, 
what will be left ? 

37. Why are acids, bases and salts said to be built on the 
water type ? 



192 A CORRESPONDENCE COURSE IN PHARMACY 

38. In what way may the highest temperature be produced 
that can be obtained by chemical means ? 

39. What is the composition of hydrogen telluride ? 

40. Write the molecular formulas of hydrogen bromide, 
hydrogen nitride, hydrogen phosphide, hydrogen silicide, 
hydrogen carbide and hydrogen boride. 

41. If the atomic weight of oxygen be set down as 100, 
what will be the corresponding atomic weight of hydrogen ? 

42. Explain why an element is said to be reduced whenever 
it enters into combination with hydrogen, but oxidized 
whenever it enters into combination with oxygen. 



LESSON FOURTEEN 
XX 

Fluorine, Chlorine, Bromine and Iodine 

291. The four elements called respectively fluorine, 
chlorine, bromine and iodine form a natural group or family 
of elements closely resembling one another in their chemical 
properties and behavior. 

292. One atom of either of these elements can hold in 
combination but one atom of hydrogen. The only possible 
hydrogen compounds of fluorine, chlorine, bromine and 
iodine are accordingly HF, HC1, HBr and HI. These 
four compounds are commonly called "acids," because they 
resemble the real acids in their power to neutralize alkalies; 
but they should instead be called the hydrogen halides, 
for they are binary compounds of the halogens, whereas 
all true acids contain more than two elements. The halides 
of hydrogen are often called the "hydrogen acids" or 
"hydracids," because they contain hydrogen without any 
oxygen, but as all acids contain hydrogen, the term "hydro- 
gen acids" is ill chosen, since its employment to distinguish 
between these compounds and the true acids rests not 
upon what they contain (H) but upon what they do not 
contain (0). 

The scientific names of HF, HOI, HBr and HI are hydro- 
gen fluoride, hydrogen chloride, hydrogen bromide and 
hydrogen iodide. 

293. All binary compounds of fluorine are fluorides; all 

193 



194 A CORRESPONDENCE COURSE IN PHARMACY * 

binary compounds of chlorine except its compounds with 
fluorine or with oxygen are chlorides ; all binary compounds 
of bromine are bromides, except its compounds with chlorine 
or fluorine (and its' compounds with oxygen, did such com- 
pounds exist) ; and all binary compounds of iodine are iodides, 
except its compounds with bromine, chlorine, fluorine or 
oxygen. 

294. A molecule of any fluoride, chloride, bromide or 
iodide may contain from one to six atoms of fluorine, 
chlorine, bromine or iodine, but never contains more than 
one atom of the positive element. A compound of fluorine 
and chlorine cannot contain more than one chlorine atom, 
but may contain one or more fluorine atoms. A chloride of 
bromine or iodine may contain one or three or five atoms 
of chlorine or bromine, but it cannot contain more than one 
iodine atom. This is because the combining value of any 
negative element in any true binary compound is unchange- 
able; the atomic combining value of the halogen in any 
halide is 1, and any member of the chlorine family of ele- 
ments (the fluorine, chlorine, bromine and iodine are together 
called the " chlorine family") having a lower atomic weight 
is negative in its chemical relation to any other element of 
the same family having a higher atomic weight. The atomic 
weight of F is 19, that of 01 is 35.5, that of Br is 80 and 
that of I is 126.5. 

295. Halogens. Fluorine, chlorine, bromine and iodine 
are called "halogens" (from hals, salt, and gennao, I 
generate), because their water-soluble binary compounds with 
the metals look like the water-soluble true salts (formed by 
true acids). But some metallic sulphides and many other 
compounds look like salts without being such. Common 
table salt is the chloride of sodium. 

But positive chlorine, bromine or iodine cannot be called 
a halogen. 



FLUORINE, CHLORINE, BROMINE AND IODINE 195 

296. Halides are the binary compounds formed by the 
metals and by hydrogen with the halogens. Sodium chloride 
is therefore a halide (from hals, salt, and eidos, like). 

297. Fluorine is a greenish-yellow gas. But very little is 
known concerning fluorine in its uncombined state, because 
the intensity of its chemical energy is so great that when 
it is set free from any one compound it cannot be prevented 
from entering at once into the formation of other compounds. 

This element occurs in nature in the form of calcium 
fluoride or fluorspar, CaF 2 , and as cryolite, which is a so-called 
"double fluoride" of aluminum and sodium. 

Its most interesting compound is the hydrogen fluoride, 
commonly called "hydrofluoric acid," which is a colorless, 
fuming, highly corrosive liquid, very poisonous because of its 
destructive chemical action. It attacks glass and is used to 
produce etchings on glassware. 

298. Chlorine is a yellowish-green gas of suffocating, char- 
acteristic odor, poisonous when inhaled. At 15° C. it can 
be compressed into a liquid under the pressure of four 
atmospheres. 

One cubic-decimeter of chlorine at 0° 0., bar. 760 mm., 
weighs about 3.17 grams. 

One volume of water at 15° C. dissolves about 2-J- volumes of 
chlorine. A water-solution saturated at 10° C. contains about 
0.6 per cent of CI. Such a solution is called "chlorine water. " 

299. Chlorine occurs most abundantly in the form of 
sodium chloride, or common salt, in sea-water and salt- 
springs, and in salt-beds or salt-mines as rock-salt. 

300. Free chlorine is commonly prepared by heating man- 
ganese dioxide, Mn0 2 > with hydrogen chloride, HC1 : 

Mn0 2 +4HCl=MnCl 2 +2H 2 0+2Cl. 

301. Chemical Properties. Chlorine displays great chemical 
energy, which fact is usually expressed by the statement that 



196 A CORRESPONDENCE COURSE IN PHARMACY 

it strongly attacks many other substances or has a destructive 
effect upon them. 

It unites with any one of all the other known elements 
(except those that form no compounds whatever, as is 
apparently the case with neon, argon, krypton and xenon). 
It displaces bromine and iodine from bromides and iodides. 

No one atom of any other element can unite with more 
than six atoms of chlorine. 

Noxious effluvia and other poisonous decomposition prod- 
ucts of organic matter are frequently unstable hydrogen 
compounds, and they may generally be destroyed by chlorine, 
because of the great affinity of chlorine for hydrogen. This 
explains the great disinfectant power of chlorine. 

302. Hydrogen chloride, HC1, is commonly called "hydro- 
chloric acid." Being very unstable or easily decomposed 
when brought in contact with certain metals and other sub- 
stances, it is described as highly corrosive or destructive. 
Iron, zinc, aluminum and several other metals readily attack 
hydrogen chloride, from which they appropriate to them- 
selves the chlorine, thus liberating the hydrogen : 

Zn+2HCl=ZnCl 2 +2H. 

303. Aqua regia is a mixture made of hydrogen chloride 
and nitric acid, and contains free CI together with nitrosyl 
chloride, ONC1. This so-called "nitrohydrochloric acid" 
dissolves gold and platinum, forming the chlorides of these 
metals. 

304. Chlorides are the compounds of negative chlorine 
with any other elements or with certain positive compound 
radicals. Among the most common chlorides are : Hydro- 
gen chloride, HC1; sodium chloride, NaCI; ammonium 
chloride or "sal ammoniac" or "muriate of ammonia,' ' 
H 4 XC1; ferric chloride, FeCl 3 ; calomel, HgCl; and corrosive 
sublimate, Hg01 2 . 



FLUORINE, CHLORINE, BROMINE AND IODINE 197 

305. Bromine is a dark-brownish-red, mobile, heavy liquid, 
which gives off suffocating yellowish-red vapors, intensely 
irritating to the eyes and the respiratory organs and 
extremely dangerous when inhaled. Its destructive action 
on organic substances, including clothing, wood, etc., render 
it imperative that bromine should be handled only with 
great caution. 

Bromine occurs in sea-water and in salt-springs chiefly in 
the form of magnesium bromide, MgBr 2 , from which the 
bromine is liberated by chlorine and in other ways. 

Bromine exhibits intense chemical energy. 

Potassium bromide, KBr, is the most common bromine 
compound. Hydrogen bromide is commonly called hydro- 
bromic acid. 

The binary compounds of the metals with bromine are 
called bromides. 

306. Iodine consists of dry, brittle, purplish-black, rhombic 
crystal plates, having a shining appearance resembling 
metallic luster, a strong, characteristic, somewhat saffron- 
like odor, and an acrid taste. 

The specific weight of iodine is 4.948 at 17° C. It melts 
at about 114° C. and boils at 200°. Its vapor is of a beauti- 
ful violet or purple color. 

It is nearly insoluble in water but soluble in alcohol. 

Iodine occurs together with chlorine and iodine in sea- 
salts and salt-springs. It also occurs in the form of sodium 
iodate in the residuary liquors obtained in separating sodium 
nitrate from the saltpetre deposits of Chili. 

From sodium iodide leached out of the ashes of seaweeds 
the iodine is obtained in the same manner as chlorine 
and bromine may be liberated from chlorides and bro- 
mides : 

2NaI+Mn0 2 +2H 2 S0 4 =MnS0 4 -f^"a 2 S0 4 +H 2 0+2I. 

The most common iodide is that of potassium, KI. 



198 A CORRESPONDENCE COURSE IN PHARMACY 

XXI 

Sulphur, Selenium and Tellurium, Phosphorus, 

Arsenic and Antimony, Carbon and 

Silicon, Boron 

307. Sulphur is at ordinary temperatures a light yellow, 
hard, odorless and tasteless solid. Its specific weight varies 
from 1.96 to 2.07. It melts at about 114° C. to an amber- 
colored liquid. When carefully fused sulphur is allowed to 
cool slowly it crystallizes, and if the still liquid portion be 
poured off before the whole mass solidifies long crystals can 
be obtained. Molten sulphur heated beyond 150° 0. darkens 
and thickens, and at nearly 200° it becomes almost black and 
so tough that it scarcely runs. Heated higher it gets thinner 
again, and if then poured into water and allowed to cool it 
forms a soft, tough, yellowish-brown solid. Sulphur boils at 
446° C. 

Brimstone is impure sulphur molded into cylindrical sticks. 

Sublimed sulphur ', or "flowers of sulphur," is a light yellow 
crystalline powder. 

Precipitated sulphur is an extremely fine, pale, greenish- 
yellow powder, without odor and taste. 

When sulphur is ignited it burns with a blue flame, forming 
sulphur dioxide, S0 2 , which may be at once recognized by 
its pungent "sulphurous" odor and irritating effects upon 
the respiratory organs. 

Sulphur is insoluble in water and in alcohol, but readily 
soluble in benzin, benzol, oil of turpentine and several 
other oils, and in ether and chloroform. 

308. Occurrence in Nature. Sulphur is found in immense 
quantities in Italy, South America, California, Louisiana 
and elsewhere. 

In combination with iron, copper, lead and zinc it occurs 
in great abundance. "Iron pyrites" is FeS 2 ; " copper 



SULPHUE, PHOSPHOKUS, ARSENIC, ANTIMONY, ETC. 199 

pyrites" is CuFeS 2 ; "galena" is PbS; and "zinc blende" is 
ZnS. 

309. Chemical Properties. Sulphur does not exhibit any- 
great inclination to form compounds with other elements 
except at high temperatures. 

Negative sulphur forms compounds whose structure is 
exactly analogous to that of the compounds of oxygen. 
These sulphur compounds are called sulphides when they 
correspond to the oxides; they are called "thio-salts" when 
analogous to oxygen salts. 

Positive sulphur is sulphur in direct combination with 
either oxygen or with one of the four halogens (fluorine, 
chlorine, bromine or iodine). One sulphur atom can hold 
in combination either two or three oxygen atoms, forming 
the two oxides, S0 2 and S0 3 . 

S0 2 forms sulphurous acid with water ; S0 3 forms sulphuric 
acid. 

310. Selenium and tellurium are rare elements which form 
compounds exactly analogous to those formed by sulphur. 

,311. Phosphorus occurs chiefly in the form of a soft white, 
or slightly yellowish, semi-translucent solid of a peculiar 
odor and taste. It emits white fumes when exposed to the 
air and on longer exposure it ignites spontaneously and 
burns with a fierce flame, forming phosphoric oxide, P 2 5 , 
which is a snow-white solid. Owing to the intense inflam- 
mability of phosphorus it must be kept under water in strong 
glass-stoppered bottles in a cool, secure place. It is very 
poisonous. 

Phosphorus is insoluble in water, but soluble in 350 parts 
of absolute alcohol at 15° C, in 80 parts of absolute ether, 
in about 50 parts of any fixed oil, and very freely in chloro- 
form and carbon disulphide. 

When the ordinary or waxy phosphorus is heated in a closed 
vessel to about 300° C. it is converted into red phosphorus, 



200 A CORRESPONDENCE COURSE IN PHARMACY 

which is an amorphous dark-red powder, not poisonous nor 
self-inflammable. 

312. Phosphorus occurs principally in the form of calcium 
phosphate in bones, and in the mineral called apatite. It is 
made from " bone-ash" or " calcined bone," which consists 
chiefly of calcium phosphate. 

313. Arsenic is an element occurring chiefly in the form 
of sulphides. The so-called "cobaltum" of commerce is 
not cobalt but an impure arsenic. 

Arsenic is a dark steel-gray, brittle solid of a somewhat 
metallic luster. It is not a metal, because it combines 
directly with hydrogen to form H 3 As, and it does not per- 
form the basic function, so that oxygen salts with arsenic as 
the basic element do not exist. 

Chemically this element is closely related to nitrogen, 
phosphorus and antimony. 

314. Compounds of arsenic are poisonous. Their structure 
is illustrated in the following examples : 

As 2 3 is arsenous oxide, commonly misnamed "arsenous 
acid." 

H 2 HAs0 3 is arsenous acid. 

K 2 HAs0 3 is potassium arsenite, contained in the medicinal 
preparation called "Fowler's Solution." 

Na 2 H As0 4 + 7H 2 is crystallized sodium arsenate. 

Na 4 As 2 7 is sodium pyroarsenate. 

315. Antimony occurs in nature chiefly as antimonous 
sulphide, called antimonite. 

This element looks decidedly like a metal, having a high 
metallic luster. It is also very heavy, its specific weight 
being 6.8. But it combines with hydrogen to form H 3 Sb, 
and it performs the basic function but feebly if at all. 

The only water-soluble antimony compound is "tartar 
emetic," which has the composition 20SbKC 4 H 4 6 -f H 2 0. 

Sb 2 S 3 is antimonous sulphide. The "black sulphide of 



SULPHUR, PHOSPHORUS, ARSENIC, ANTIMONY, ETC. 201 

antimony" is crystallized antimonous sulphide. Precipitated 
antimonous sulphide is yellowish-red. 

Sb 2 3 is antimonous oxide. 

Sb 2 S 5 is antimonic sulphide. 

SbCl 3 is antimonous chloride. 

316. Carbon is an element common to all vegetable and 
animal substances. In its free state it exists in several 
forms, viz. : diamond, graphite, soft coal, hard coal and peat. 
Coke, wood charcoal, animal charcoal and lampblack are 
also carbon. 

Combined carbon is contained not only in all vegetable and 
animal substances but also in limestone, chalk, marble, 
magnesite, etc. 

In its ordinary forms carbon is a solid, inodorous, tasteless 
substance, insoluble in all liquids, infusible and non-volatile. 
When heated strongly in the air it ignites and burns, form- 
ing C0 2 if the supply of air or oxygen is abundant, but CO 
if the supply is deficient. 

317. The chemical properties of carbon are extraordinary. 
At common temperatures it shows no chemical energy ; but 
at a high heat it readily combines with oxygen, forming 
either C0 2 or CO, according to whether the supply of oxygen 
is liberal or deficient. It, therefore, has two combining 
values, 4 and 2. But the valence of the carbon atom in 
nearly all known carbon compounds is 4. The most remark- 
able characteristics of carbon are that its atoms can hold 
each other in combination to form chains or rings which give 
character to innumerable organic substances, and that the 
same carbon atom can hold in combination with itself both 
positive and negative elements at the same time. Thus 
hydrogen, which is positive, and oxygen, which is negative, 
can both be held in combination with the same carbon atom, 
as in H 3 COH. 

318. The compounds formed by carbon with hydrogen 



202 A CORRESPONDENCE COURSE IN PHARMACY 

alone are called hydrocarbons. The simplest of these is H 4 C, 
because it contains but one carbon atom. Hydrocarbons 
containing a small number of carbon atoms are gases ; others, 
with a larger proportion of carbon, are liquid; and those 
containing much carbon are solids. 

Coal oil is a mixture of hydrocarbons. Benzin, gasolin, 
petrolatum, paraffin, naphthaline, terebene and benzol are 
all hydrocarbons. Nearly all volatile oils contain one or 
more kinds of hydrocarbons. The coal gas used for illumina- 
tion -and for fuel is a mixture of gaseous hydrocarbons of 
which the chief is H 4 C. 

Carton monoxide, or carbonous oxide, is CO— a colorless, 
odorless, tasteless gas which burns with a blue flame, forming 
C0 2 . The CO is poisonous when inhaled. When steam is 
blown through incandescent coal or coke, the water (steam) 
is decomposed and the products are H and CO, which 
together constitute the gaseous mixture called water gas. 

Carbon dioxide, C0 2 , is present in the air because animals 
exhale it. C0 2 is also produced in the decay of certain 
organic substances and by combustion. The C0 2 is com- 
monly called "carbonic acid gas," because when dissolved in 
water it forms a solution of carbonic acid, H 2 C0 3 . Carbonic 
acid water is a refreshing and not unwholesome drink; but- 
when inhaled the gas C0 2 is poisonous, and even a small pro- 
portion of it renders air unfit to be breathed. Effective 
ventilation is necessary to remove the air contaminated with 
the C0 2 injected into it by respiration. Men and animals 
inhale air and exhale carbon dioxide. Plants decompose the 
carbon dioxide, appropriating the carbon and restoring the 
oxygen to the air. 

Cyanogen, (CN) 2 , is a colorless gas of irritating odor and 
very poisonous. HCN is the fearfully poisonous hydrogen 
cyanide, commonly called "hydrocyanic acid," or "prussic 
acid." 



SULPHUR, PHOSPHORUS, ARSENIC, ANTIMONY, ETC. 203 

319. Silicon is, next to oxygen, the most abundant of all 
elements. Silica, Si0 2 , and silicates of several kinds, con- 
stitute a large proportion of the rock, sand and clay forma- 
tions of the earth's surface. Quartz, flint, sand and agate 
are different forms of silicon dioxide or silica. 

Brick, earthenware, porcelain and glass are mixtures of 
silicon compounds. The chief constituents of glass are the 
silicates of potassium, sodium, calcium and lead. The pure 
silicates of potassium and sodium are water-soluble, but 
mixtures of them with the silicates of calcium and lead are 
not only insoluble in water but even resist the action of strong 
acids and alkalies to a remarkable degree. 

320. Boron is an element that occurs chiefly in the com- 
pound called lorax, which is sodium tetraborate, Na 2 B 4 7 . 
Boric acid is H 3 B0 3 , or, rather, (HO) 3 B. 

Boric acid is a remarkable antiseptic and hence used in 
large quantities as a preservative of meats and other perish- 
able organic substances and also as a harmless and yet effective 
constituent of antiseptic lotions, dressings and powders. 

Test Questions 

1. Name the halogens. 

2. What is the correct scientific name for hydrobromic acid ? 

3. What is the maximum number of chlorine atoms that 
can be contained in a chloride ? 

4. What is the maximum number of atoms of the positive 
element in any true iodide ? 

5. How can tri-iodide of chlorine be made ? 

6. What is the most common fluorine compound in nature ? 

7. What is the most abundant chloride ? 

8. How is chlorine produced ? 

9. How is the great power of chlorine as a disinfectant 
explained ? 



204 A CORRESPONDENCE COURSE IN PHARMACY 

10. What is formed when iron is dissolved in a solution of 
hydrogen chloride ? Write the equation representing the 
chemical reaction. 

1 1 . What is the algebraic combining number of the nitrogen 
in nitrosyl chloride ? 

12. Write the formulas for mercurous chloride and mer- 
curic chloride ; for ferrous chloride and ferric chloride. 

13. What is the action of chlorine on water ? 

14. Why is chlorine recognized as a powerful oxidizing 
agent ? 

15. Write the formula for ammonium bromide. 

16. How is bromine liberated from a bromide ? 

17. Describe bromine. 

18. How does it differ from chlorine and iodine ? 

19. What are the sources of iodine? 

20. What is the chemical action of bromine on potassium 
iodide ? 

21. What is the percentage of bromine in a 10 per cent 
solution of hydrogen bromide ? 

22. What is the percentage of bromine in potassium 
bromide ? 

23. Which contains the greater amount of iodine, a syrup 
containing 10 per cent of hydrogen iodide or the compound 
known as potassium iodide ? 

24. Which of the two compounds, potassium chloride and 
potassium chlorate, is best able to resist decomposition when 
exposed to strong heat ? 

25. Describe S0 2 and state how it is produced. 

26. What is the difference between a carbonate and a 
thio-carbonate ? 

27. What is the difference between positive sulphur and 
negative sulphur ? 

28. What is the difference between sulphuric sulphur and 
hyposulphurous sulphur ? 



SULPHUR, PHOSPHORUS, ARSENIC, ANTIMONY, ETC. 205 

29. What is formed when S0 3 is added to water ? 

30. Write the chemical reaction occurring when S0 2 is 
dissolved in water. 

31. Name the several possible products formed from S0 3 
and water. 

32. Can you name any compound containing both positive 
sulphur and negative sulphur ? 

33. Describe phosphorus. 

34. What are the differences between the two allotropic 
modifications of phosphorus ? 

35. What is the most common source of phosphorus ? 

36. How many bonds has the phosphorus atom in HPH 2 2 ? 

37. How many bonds has the phosphorus in H 3 P0 2 ? 

38. How many bonds does the phosphorus have in 
HOP0 2 ? 

39. How many bonds does the phosphorus have in H 2 PH0 3 ? 
How many in H 3 P0 3 ? 

40. How many bonds does the phosphorus have in H 5 P0 5 ? 
InH 3 P0 4 ? InHP0 3 ? 

41. Give the technical names of all the phosphorus com- 
pounds represented by the formulas in questions 36-40. 

42. What is the difference between the phosphorus in a 
metaphosphite and the phosphorus in any phosphate ? 

43. Write the molecular formula for nitrate of arsenic. 

44. Write the molecular formula for arsenous hydroxide. 

45. If hydrogen arsenide is H 3 As, what possible combining 
values can the arsenic have when united to oxygen ? 

46. Why is the formula for arsenous acid written H 2 HAs0 3 
instead of H 3 As0 3 ? 

47. Can that formula be written more scientifically than 
it is in either of the forms given in the preceding ques- 
tion? 

48. Why is As 2 3 not an acid? 

49. Antimony is a very heavy, brilliantly metallic looking 



206 A CORRESPONDENCE COURSE IN PHARMACY 

substance and forms several useful alloys. Why, then, is it 
not a metal, chemically as well as physically ? 

50. What is an antimonide ? 

51. What is the difference between antimonous oxide and 
antimonic oxide ? 

52. Name several carbon compounds contained in the 
mineral world. 

53. Mention several forms of free carbon found in nature. 

54. What is the algebraic combining number of the carbon 
atominH 3 COH? 

55. Why are the hydrocarbons so useful as fuel? 

56. What is carbonic acid ? 

57. What is carbonic acid gas ? 

58. How is the 00^ exhaled by men and animals removed 
from the atmosphere ? 

59. What is hydrocyanic acid ? 

60. What is the algebraic combining number of the carbon 
in a molecule of the so-called hydrocyanic acid ? 

61. What is silica? 

62. What is the composition of glass ? 

63. What are the principal uses of boric acid ? 

64. What is the algebraic combining number of each 
boron atom in borax ? 



LESSON FIFTEEN 

To the Student: 

The section numbered XXIV, which treats of the solubilities of com- 
mon inorganic chemical compounds in water and in alcohol, is included 
in this lesson principally because of its value as a matter of reference 
for students. It is full of facts a knowledge of which the student 
should have, but as the mastering of it is a pure matter of memory, 
no questions are given upon it. It is not expected, moreover, that 
the student will memorize the chapter, but will keep it available for 
frequent reference in subsequent lessons, and it is certain that he will 
find the matter useful in examinations and in future work. 



XXII 

The Light Metals 

321. The light metals are those whose specific weights are 
less than 5 and lower than the specific weights of their own 
oxides. The most important light metals are lithium, 
sodium, potassium, magnesium, calcium, strontium, barium 
and aluminum. 

All of these metals have a constant valence. 

322. The alkali metals are lithium, sodium, potassium, 
rubidium and caesium. The two last mentioned are rare. 
Potassium and sodium are abundant. 

All of them are monads or have an atomic combining value 
of 1, for their oxides are Li 2 0, Na 2 0, K 2 0, Kb 2 and Cs 2 0. 
Their hydroxides are the true alkalies, which are freely 
water-soluble. The alkali metals have such an intense 
affinity for oxygen that they must be excluded from contact 

207 



208 A CORRESPONDENCE COURSE IN PHARMACY 

with air, and this is effected by keeping them immersed in 
kerosene or benzin. When put in water they decompose it, 
combining with hydroxyl and liberating one hydrogen atom 
from each molecule of water decomposed : 

HOH + K = KOH + H. 

323. Potassium is a soft silver-white metal, lustrous when 
freshly cut but tarnishing rapidly in the air. It is kept 
immersed in benzin to prevent its oxidation. The specific 
weight of K is 0.86. 

324. Occurrence. Potassium is a widely distributed metal. 
Potassium silicate occurs in granite rocks, and plants grow- 
ing in the soils derived from such rocks yield an ash contain- 
ing potassium carbonate. This is leached out from wood 
ashes with water and the solution boiled down to get the 
crude potassium carbonate which is called "potash." The 
metal itself derives its name from the potash. Potassium 
is also contained in "argols" or crude "tartar," which is 
the bitartrate of potassium deposited from the fermenting 
grape juice in the process of making wine. Purified by 
recrystallization, the crude tartar is called "cream of tartar." 
But the present source of potassium is the potassium chloride 
associated with other salts in the salt beds at Stassfurt, 
Germany. 

325. Potassium compounds are white or colorless unless 
they contain other elements which impart color. They are 
nearly all very readily water-soluble, and several common 
potassium compounds are, in fact, deliquescent. 

Among the most common compounds of potassium are: 
KOH, potassium hydroxide, called "caustic potash." 
K 2 C0 3 , the carbonate of potassium, or "potash." 
KHC0 3 , bicarbonate of potassium. 
KBr, potassium bromide. 
KI, potassium iodide. 



THE LIGHT METALS 209 

KN0 3 , potassium nitrate, or "niter," or " saltpetre." 
KCIO3, potassium chlorate. 

326. Sodium is very like potassium, but does not decompose 
water so violently. Its specific weight is 0.97. 

It occurs abundantly in the form of common "salt," which 
is sodium chloride, in sea-water and in salt-springs and salt- 
beds. Sodium nitrate is found in Chili in the form called 
"Chili saltpetre." 

Common "washing soda" is sodium carbonate, which is 
manufactured on an immense scale from sodium sulphate 
made out of sodium chloride, or the carbonate may be made 
direct from sodium chloride. 

327. Sodium compounds are white or colorless and generally 
very readily water-soluble. 

The most common include : 

NaOH, sodium hydroxide, or "caustic soda." 

Na 2 C0 3 -l- 10II 2 O, sodium carbonate, which constitutes "sal 
sodae" or washing soda. 

NaHC0 3 , sodium bicarbonate, or "baking soda." 

NaCI, "common salt." 

Na 2 SO 4 + 10II 2 O, sodium sulphate, or "Glauber's salt." 

Na 2 S0 3 S + 5H 2 0, sodium thio- sulphate, commonly but 
erroneously called "hyposulphite of sodium" (which is 
Na 2 S0 2 — quite another substance). 

NaN0 3 , sodium nitrate, or "Chili saltpetre." 

Na 2 HP0 4 -f 12H 2 0, sodium phosphate. 

Na 2 B 4 O 7 + 10H 2 O, sodium tetraborate, or "borax." 

NaC 18 H 33 2 , sodium oleate, the chief constituent of com- 
mon hard soap, such as "Castile soap." 

328. Lithium is, like potassium and sodium, a soft silver- 
white metal. It is comparatively rare and costly. Its specific 
weight is 0.589. 

Its compounds are white or colorless. They are not as 
generally or freely soluble as the compounds of potassium 



210 A CORRESPONDENCE COURSE IN PHARMACY 

and sodium. One of the most striking properties of lithium 
salts is the beautiful crimson color they impart to flame. 

329. The Alkaline Earth Metals. These are barium, 
strontium and calcium. They have an atomic combining 
value of 2, for their oxides are BaO, SrO and CaO. 

The hydroxides of these metals are sparingly water-soluble, 
but the solutions have a strongly alkaline character. 

Like the alkali metals, they decompose water, but much 
more quietly. 

330. Barium is a soft, yellowish metal of the specific weight 
4. It occurs in "heavy spar," which is barium sulphate, in 
caves on Put-in-Bay Island, Ohio. 

The most common compounds of barium are : 

BaO, barium oxide, or "baryta." 

BaC0 3 , barium carbonate. 

BaCl 2 + 2H 2 0, barium chloride. 

Ba(N0 3 ) 2 , barium nitrate. 

BaS0 4 , barium sulphate. 

331. Strontium is comparatively rare. It is a soft, yellowish 
metal having the specific weight 2.5. Its compounds are 
analogous to those of calcium and barium. 

332. Calcium is a soft, yellowish metal of the specific weight 
1.6. It may be kept in dry air without oxidation, but 
decomposes water rapidly : 

2H 2 + Ca = Ca(OH) 2 + 2H. 

It occurs abundantly in the form of limestone, chalk and 
marble, all of which are calcium carbonate. Igneous rocks 
contain calcium silicate and other calcium compounds. 
"Gypsum" is calcium sulphate, and dried gypsum is nearly 
anhydrous or water-free calcium sulphate, which, when 
mixed with the proper amount of water, forms normal 
calcium sulphate, commonly called crystallized calcium sul- 
phate or "plaster of Paris." Quick lime, or building lime, is 



THE LIGHT METALS 211 

calcium oxide, and slaked lime is calcium hydroxide. Hy- 
draulic cement is made by calcining limestone containing clay 
and silica; this cement hardens when mixed with water, 
forming calcium silicate and carbonate. 

333. Calcium compounds are white or colorless. The car- 
bonate, phosphate and oxalate are insoluble ; hydroxide and 
sulphate are sparingly soluble. 

Among the most common calcium compounds are : 

CaO, calcium oxide, calx, or "lime." 

Ca(OH) 2 , calcium hydroxide, "slaked lime." "Lime 
water" is a solution of calcium hydroxide. 

CaCl 2 , calcium chloride. 

CaC0 3 , calcium carbonate, marble, chalk, limestone. 

CaH 4 S0 6 (or CaS0 4 4-2H 2 0), calcium sulphate or "gyp- 
sum." 

CaS0 4 , dried calcium sulphate, used for making "plaster 
of Paris" by mixing the dry powder with water. 

Oa 3 (P0 4 ) 2 , calcium phosphate, which is the chief inorganic 
constituent of bone. 

Ca(C10) 2 , calcium hypochlorite, the valuable constituent 
of the so-called "chloride of lime" or "bleaching powder," 
which also contains CaCl 2 . 

334. Magnesium is a white metal which oxidizes but slowly 
in moist air. Can be made into wire and ribbons, and con- 
verted into coarse powder. Its specific weight is 1.74. It 
does not decompose water at the ordinary temperatures, but 
does so at the boiling point of. the water. 

The "flash-light" of photographers is produced by burning 
powdered magnesium. 

Magnesium occurs in large quantities, chiefly in the form 
of carbonate and silicate. 

Magnesite is magnesium carbonate. "French chalk" or 
"talcum," and also "asbestos" and "meerschaum," are 
magnesium silicate. 



212 A CORRESPONDENCE COURSE IN PHARMACY 

335. Magnesium compounds are white or colorless. The 
oxide, hydroxide, carbonate, phosphate and oxalate are 
insoluble in water. The citrate is also practically insoluble 
in water, but the " solution of citrate of magnesium" of the 
drug stores is made by adding a large excess of citric acid, 
which holds the magnesium citrate in solution in the water. 

Among the most common magnesium compounds are: 

MgO, magnesium oxide, commonly called "calcined 
magnesia." 

MgH 2 S0 5 + 6H 2 (commonly represented as MgS0 4 + 
7H 2 0) is magnesium sulphate, or "Epsom salt." 

Mg 5 (OH) 2 (C0 3 ) 4 + 5H 2 is the common carbonate of mag- 
nesium. 

336. Aluminum is a silver-white metal which is malleable, 
ductile and capable of high polish. It is not tarnished in 
dry, pure air. Its specific weight is 2.5. It is strong, tough, 
durable and light, and as it does not corrode in the air and 
is not easily affected by other substances except chlorides, it 
is an extremely useful metal. 

This metal occurs abundantly in combination with oxygen 
and silicon. Clay consists of aluminum silicate. Cryolite 
is 3XaF. A1F 3 . Beauxite is A1 2 3 + H 2 0. Aluminum oxide, 
commonly called "alumina," occurs as emery, corundum, 
sapphire and ruby Feldspar. and mica contain aluminum, 
and "thina clay" or "pipe clay" or "kaolin" are also 
aluminum compounds. The metal is named after "alum." 

337. Aluminum salts are white or colorless. Those soluble 
in water are astringent. 

The structure of aluminum compounds is illustrated by 
the following common compounds: 

A1 2 3 , aluminum oxide. 

Al(OH) 3 , aluminum hydroxide, commonly misnamed 
"aluminum hydrate." 

A1C1 3 , aluminum chloride. 



THE HEAVY METALS 213 

A1K(S0 4 ) 2 + 12H 2 0, aluminum and potassium sulphate, or 
alum, or " potash-alum." 

A1II 4 N(S0 4 ) 2 4- 12H 2 0, aluminum and ammonium sulphate, 
or "ammonia alum," the now common alum. 



XXIII 

The Heavy Metals 

338. The heavy metals are those whose specific weights 
exceed 5 and are higher than those of their oxides. The 
heavy metals of great importance include zinc, iron, nickel, 
chromium, manganese, lead, copper, mercury, silver, gold, 
platinum, bismuth and tin. 

The compounds of the heavy metals are not as generally 
water-soluble as are the compounds of the light metals, and 
the compounds of metals of very high atomic weights as well 
as specific weights form very few water-soluble compounds. 

The light metals form more powerful bases than the 
heavy metals. 

339. Zinc is a bluish-white, crystalline, lustrous, brittle 
metal of the specific weight 7.2. It melts at 412° C. It 
readily decomposes dilute acids, and also the alkalies in hot 
solutions. 

Zinc occurs as zinc Mende, which is sulphide of zinc, and 
also as calamine, which is composed of carbonate and silicate. 

340. Zinc compounds are generally white or colorless. The 
water-soluble salts of zinc have a disagreeable, bitter, 
astringent, metallic taste, and are poisonous. 

Among the most common zinc compounds we have : 
ZnO, zinc oxide. 
ZnCl 2 , zinc chloride. 

ZnH 2 S0 5 + 6H 2 (commonly represented as ZnS0 4 + 7H 2 0) , 
zinc sulphate, or "white vitriol." 



214 A CORRESPONDENCE COURSE IN PHARMACY 

341. Iron is. light grayish, lustrous, hard, malleable, ductile, 
tenacious. Its specific weight is from 7.3 to 7.9. It melts 
at about 2000° C. 

Wrought iron, steel and cast iron all contain carbon and 
minute amounts of other elements. Wrought iron contains 
the smallest proportion of carbon ; cast iron the greatest. 

Iron occurs in very large quantities in the form of oxides, 
hydroxides, carbonates and sulphides. The best iron ore is 
"magnetic iron ore," which has a composition represented 
by Fe 3 4 . 

342. Iron compounds are of various colors — white, gray, 
green, yellow, red, brown, blue, black, purple and rose. 

Ferrous compounds contain iron with a valence of 2. They 
are generally white or grayish-white when anhydrous, but 
green or greenish-blue when hydrous or in water solution. 

Ferric compounds contain iron with a valence of 3. They 
are usually nearly white or pale yellow when anhydrous, but 
red-brown when associated with water. 

The iron preparations used in medicine are numerous. 
Among the most common compounds of iron are the fol- 
lowing: 

FeCl 2 , ferrous chloride. 

Fel 2 , ferrous iodide. 

FeH 2 S0 5 + 6H 2 (commonly written FeS0 4 + 7H 2 0), 
ferrous sulphate, or "green vitriol." ' 

FeH 2 S0 5 , dried or anhydrous ferrous sulphate. 

Fe 2 3 , ferric oxide. 

FeCl 3 , ferric chloride. 

Fe(OH) 3 , ferric .hydroxide, commonly misnamed "ferric 
hydrate." 

Fe 2 (S0 4 ) 3 , ferric sulphate. 

343. Nickel is a hard silver-white metal, tough, capable 
of high polish. Its specific weight is 8.9. 

The principal nickel ore is nickelic arsenide, NiAs. 



THE HEAVY METALS 215 

344. Chromium is a hard, gray, crystalline, infusible powder 
of the specific weight 7.3. 

Chromous compounds contain the metal with a valence of 
2, as in CrCl 2 . In chromic compounds the element has a 
valence of 3, as in Cr 2 3 . But potassium dichromate (com- 
monly misnamed "bichromate") has the composition K 2 Cr 2 7 , 
and "chromic anhydride" is Cr0 3 , which is commonly 
misnamed chromic acid. 

345. Manganese is a hard, brittle metal, fusible with diffi- 
culty. It occurs in nature in combination with oxygen. Its 
specific weight is about 7.5. 

Manganese is remarkable because of its many different 
valences. It can apparently have a valence of either 2, 3, 
4, 6 or 7. 

MnO is manganous oxide. 

Mn 2 3 is manganic oxide. 

Mn0 2 is manganese dioxide. 

MnS0 4 is manganous sulphate. 

K 2 Mn0 4 is potassium manganate. 

KMn0 4 is potassium permanganate. 

346. Lead is a soft, gray or bluish- white metal of bright 
luster when untarnished. Its specific weight is 11.4, and 
its melting point 330° 0. 

The principal lead ore is galena, which is PbS. 

The only water-soluble lead compounds are the acetate 
and the nitrate. 

PbO is oxide of lead, familiar in the form of the red 
"litharge" and the yellow "massicot." 

"White lead" is a "basic carbonate of lead." 

"Red lead" or "minium" is Pb 3 4 . 

Lead compounds are poisonous. 

347. Copper is reddish, softer than iron but harder than 
silver, malleable and ductile, capable of high polish. Its 
specific weight is 8.9, and its melting point about 1090°. 



216 A CORRESPONDENCE COURSE IN PHARMACY 

It is found in large quantities, uncombined, in the great 
copper mines of the Lake Superior regions and in other places. 
Copper pyrites is represented by the formula CuFeS 2 and is 
common. 

Brass is an alloy of copper and zinc. 

348. Copper compounds are generally green or blue, but 
some are white, red, brown or black. 

Cuprous copper is a monad; cupric copper a dyad. 

Soluble copper compounds have a nauseous, strongly 
"metallic" or "brassy," persistent taste, and are poisonous. 

Among the very common copper compounds are the 
following : 

Cu 2 0, cuprous oxide. 

CuO, cupric oxide. 

Cu 2 S, cuprous sulphide. 

CuS, cupric sulphide. 

Cu(N0 3 ) 2 , cupric nitrate. 

CuS0 4 , anhydrous cupric sulphate. 

CuS0 4 + 5H 2 0, crystallized cupric sulphate, or "blue 
vitriol." 

349. Mercury is the only metal which is liquid at the 
ordinary temperatures. It is silver- white, lustrous, and so 
mobile that it is called "quick silver." Its specific weight 
is 13.6, and its boiling point 360° C. It freezes at about 
-40° C. 

Cinnabar is the crystallized mercuric sulphide found in 
nature and this constitutes the ore from which the metal is 
obtained. 

350. Mercury compounds are of two classes, according to 
the valence of the element. Mercurous mercury is a monad, 
forming mercurous compounds; mercuric mercury is the 
metal with a valence of 2, forming mercuric compounds. 

The only water-soluble mercury compounds are mercuric 
chloride and mercuric cyanide; but the nitrates, both 



THE HEAVY METALS 217 

mercurous and mercuric, can be dissolved in a mixture of 
nitric acid and water. 

Mercury compounds have a great variety of colors : color- 
less, white, scarlet, crimson, gray, yellow, orange red, black 
and brown. 

They are poisonous, except when absolutely insoluble. 

Among the most common mercury compounds are : 

HgOl, mercurous chloride or "calomel." 

Hgl, mercurous iodide. 

HgO, mercuric oxide, which is red if produced "in the 
dry way," but yellow if made by precipitation. Eed oxide 
of mercury is often called "red precipitate," but cannot be 
made by "precipitation" as we now understand that term. 

HgCl 2 , mercuric chloride or "corrosive sublimate." 

Hgl 2 , mercuric iodide, or "red iodide of mercury." 

HgS, mercuric sulphide, which is red when crystallized, 
but black when precipitated, although the black precipitated 
mercuric sulphide can be converted into a red powder called 
"vermilion." 

H 2 NHgCl is mercuric chloramide, commonly called "white 
precipitate. ' ' 

351. Silver is a beautiful white metal, harder than gold, 
capable of very high polish, malleable and ductile. . Its 
specific weight is 10.6, and its melting point about 916° 0. 
It is the best known conductor of heat and of electricity. 

Pure silver is called "sterling silver." 

This metal occurs in nature in the free state, but more 
freely in the form of sulphide associated with the sulphides 
of lead and copper. 

352. Silver compounds are colorless, white, black, yellow 
or brown. As silver is univalent, the structure of its 
compounds is simple : 

Ag 2 is silver oxide. 
AgOl, silver chloride. 



218 A CORRESPONDENCE COURSE IN PHARMACY 

AgX0 3 , silver nitrate, which, when molded into pencils, 
is called "lunar caustic." 

353. Gold is soft, yellow, capable of extremely high polish, 
remarkably malleable and ductile. Its specific weight is 
19.3. It melts at about 1037° 0. 

Pure gold does not decompose acids, but it dissolves in the 
mixture called "aqua regia," which is made of nitric acid 
and hydrochloric acid, because that mixture contains free 
chlorine, with which the gold forms a soluble chloride. 

Gold occurs in nature almost exclusively in the uncombined 
state. 

The most common gold compound is the chloride, AuCl 3 , 
which is a light yellow, transparent, water-soluble, crystalline 
solid. 

354. Platinum is a grayish-white, lustrous, hard, tough 
metal, fusible only at a strong white heat. Its specific 
weight is 21.46. It occurs in nature only in the free state. 
It dissolves in "aqua regia" to form platinic chloride, PtCl 4 . 

355. Bismuth occurs in nature only in the uncombined 
state. It is a reddish-white, brittle metal of high luster and 
well defined crystalline structure. It is not malleable nor 
ductile. It has the specific weight 9.74. It is easily fused, 
its melting point being 270° 0. It readily decomposes 
nitric acid, forming nitrate of bismuth, which is soluble in 
water mixed with nitric acid, but converted into subnitrate 
of bismuth by water alone. 

Bi 2 3 is bismuth oxide. 
OBiCl is bismuthyl chloride. 
Bi(N0 3 ) 3 , bismuth nitrate. 

OBiN0 3 , bismuthyl nitrate, or "subnitrate of bismuth." 
(OBi) 2 C0 3 +H 2 0, "subcarbonate of bismuth," or bismuthyl 
carbonate. 

356. Tin is a silver-white, lustrous, soft, malleable metal, 
of the specific weight 7.3, fusible at 228° C. It occurs in 



SOLUBILITIES OF COMMON INOKGANIC COMPOUNDS 219 

nature in the form of "tin ore" or "tin-stone," which is 
stannic oxide, Sn0 2 . 

Tin is not easily oxidized, nor is it affected by organic 
substances which attack iron, copper, lead, zinc, etc. 
Hence its great usefulness. 

"Tin salt" is stannous chloride, SnCl 2 + 2H 2 0. 



XXIV 

Solubilities of Common Inorganic Chemical 
Compounds in Water and in Alcohol 

WATER SOLUBILITIES 

357. Potassium Compounds. All are water-soluble and 
most of them are readily soluble. 

Deliquescent are the hydroxide, carbonate, cyanate, phos- 
phate, hypophosphite, acetate and the sulphated potassa. 

Readily soluble are the bicarbonate, chloride, bromide, 
iodide, ferricyanide, ferrocyanide, nitrate, tartrate, citrate, 
salicylate, benzoate and Rochelle salt. 

Less readily soluble are sulphate in 9.5 parts of water, 
dichromate in 10 parts of water, permanganate in 16 parts of 
water and chlorate in 16.7 parts of water. 

Very sparingly soluble is cream of tartar in 201 parts of 
water. 

Nearly insoluble is potassium-platinum chloride. 

358. Sodium Compounds. All are soluble except anti- 
monite, which is nearly insoluble. 

Very freely soluble are the hydroxide, carbonate, chloride, 
bromide, iodide, chlorate, sulphate, sulphite, bisulphite, 
thio-sulphate, nitrate, nitrite, phosphate, hypophosphite, 
arsenate, acetate, tartrate, citrate, valerate, salicylate and 
benzoate and Rochelle salt. 



220 A CORRESPONDENCE COURSE IN PHARMACY 

Less readily soluble are bicarbonate in 11.3 parts of water, 
pyrophosphate in 12 parts of water, borax in 16 parts of water 
and bitartrate sparingly. 

359. Lithium Compounds. All freely soluble in water 
except the carbonate, which dissolves in 80 parts of water, 
and the phosphate, which is nearly insoluble. 

360. Ammonium Compounds. All officinal ammonium 
compounds are readily water-soluble, the least soluble being 
the benzoate and the carbonate, which are soluble in 5 parts 
of water. 

361. Barium Compounds. The nitrate, chloride, bromide, 
iodide, sulphide and acetate are readily soluble. The hy- 
droxide is soluble in 20 parts of water. 

Insoluble are the carbonate, phosphate, sulphate and 
oxalate. 

362. Strontium Compounds. The chloride, bromide and 
iodide are deliquescent. The acetate, lactate and nitrate 
are readily soluble. The hydroxide is comparatively sparingly 
soluble. 

Insoluble are the carbonate, phosphate, sulphate and 
oxalate. 

363. Calcium Compounds. Deliquescent are the chloride, 
bromide and iodide. Eeadily soluble are the nitrate, hypo- 
phosphite, sulphite, acetate, lactate and the sulphurated 
lime. Sparingly soluble is the hydroxide, which requires 
from 600 to 700 parts of water for solution, and the sulphate, 
which is soluble in from 300 to 400 parts of water. Insoluble 
are the carbonate, oxalate and phosphate. 

364. Magnesium Compounds. Eeadily soluble are the 
chloride, bromide, iodide, nitrate, sulphate, acetate, lactate 
and the acid citrate. Insoluble are the oxide, hydroxide, 
carbonate, oxalate and phosphate. 

365. Zinc Compounds. Deliquescent are the chloride, 
bromide and iodide. Eeadily soluble are the sulphate, 



SOLUBILITIES OF COMMON INORGANIC COMPOUNDS 221 

nitrate, acetate, lactate and paraphenolsulphonate. Less 
readily soluble is the valerate. Insoluble are the oxide, 
sulphide, phosphide, hydroxide, carbonate, oxalate, phos- 
phate and oleate. 

366. Cadmium Compounds. Soluble are the chloride, bro- 
mide, iodide, nitrate and sulphate. Insoluble are the oxide, 
hydroxide, sulphide, carbonate, oxalate and phosphate. 

367. Aluminum Compounds. Eeadily soluble are the 
chloride, bromide, iodide, nitrate, sulphate, acetate, potash 
alum and ammonia alum. Insoluble are the oxide and 
hydroxide. 

368. Cerium Compounds. Soluble are the chloride, nitrate 
and sulphate. Insoluble are the oxide, hydroxide, carbonate 
and oxalate. 

369. Cobalt Compounds. The cobaltous salts and halides 
are deliquescent. Insoluble are the oxides, hydroxides and 
sulphides. 

370. Nickel Compounds. Mckelous sulphate and nickel- 
ous chloride are soluble. The oxides, hydroxides and sul- 
phide of nickel are insoluble. 

371. Iron Compounds. Very readily water-soluble are 
ferrous chloride, bromide and iodide, ferrous sulphate and 
nitrate, ferric chloride and bromide, ferric nitrate, subsul- 
phate, sulphate, acetate and citrate, and iron alum. The 
scale-salts of iron are all freely soluble. 

Less soluble is ferrous lactate, requiring 40 parts of water 
for solution. 

The insoluble iron compounds are ferrous and ferric 
oxides, hydroxides, sulphides, carbonates, oxalates, phos- 
phates, pyrophosphates, metaphosphates andhypophosphites. 

372. Chromium Compounds. Water-soluble are the chlo- 
rides, chromium sulphate, chromic anhydride, commonly 
called chromic acid, potassium chromate, potassium dichro- 
mate and chrome alum. 



222 A CORRESPONDENCE COURSE IN PHARMACY 

373. Manganese Compounds. Soluble are manganous 
chloride, bromide, iodide, nitrate and sulphate; also potas- 
sium manganate and permanganate and sodium perman- 
ganate. Insoluble are the oxides, hydroxide, carbonate, 
oxalate, phosphate and sulphide. 

374. Lead Compounds. The only readily water-soluble lead 
compounds are the nitrate, acetate and subacetate. Lead 
chloride is sparingly soluble. 

375. Copper Compounds. The only water-soluble cupric 
compounds are the chloride, nitrate, sulphate and acetate. 

376. Mercury Compounds. All mercurous compounds are 
insoluble in water, but mercurous nitrate is soluble in a 
mixture of water and nitric acid. 

The only water-soluble mercuric compounds are the chlo- 
ride, which is soluble in 16 parts of water, and the acetate 
and cyanide. The bromide is soluble in about 200 parts of 
water, but mercuric nitrate is soluble in a mixture of nitric 
acid and water. 

377. Silver Compounds. The only water-soluble salts are 
the nitrate and acetate. 

378. Gold Compounds. The only water-soluble gold com- 
pound much in use is the trichloride. 

379. Bismuth Compounds. The only water-soluble bismuth 
compound is citrate of bismuth and ammonium. But the nor- 
mal bismuth nitrate which is decomposed by water is soluble 
in glycerin and also in glacial acetic acid without decomposi- 
tion. It is also soluble in a mixture of nitric acid and water. 

380. Antimony Compounds. The only water-soluble anti- 
mony compound is tartrate of antimonyl and potassium, 
commonly called tartar emetic. But chloride of antimony is 
soluble in a mixture of hydrogen chloride and water. 

381. Arsenical Compounds. Sodium arsenate is readily 
soluble. Potassium arsenite is also soluble, as is iodide of 
arsenic. Arsenous acid is only sparingly soluble. 



SOLUBILITIES OF COMMON" LSTOKGANIC COMPOUNDS 223 

382. Oxides. No metallic oxides are water-soluble, except 
chromic anhydride and other oxides that react with the 
water to form either acids or bases. These dissolve by 
"chemical solution. " 

383. Hydroxides. The only freely water-soluble metallic 
hydroxides are those of the alkali metals. The hydroxides 
of barium, strontium and calcium are comparatively sparingly 
or very sparingly soluble. All other metallic hydroxides are 
insoluble. 

384. Chlorides. All metallic chlorides are water-sol- 
uble except those of silver and lead, mercurous chloride 
and the chloride of antimony (which is decomposed by 
water, but soluble in a mixture of hydrochloric acid and 
water) . 

Deliquescent chlorides are those of calcium, zinc, ferric 
chloride and platinic chloride. 

Eeadily soluble are the chlorides of potassium, sodium, 
lithium, ammonium, barium, strontium, magnesium, alumi- 
num and gold. 

Less readily soluble is mercuric chloride, soluble in 16 
parts of water. 

Nearly insoluble is lead chloride. 

Insoluble are silver chloride and mercurous chloride. 

Decomposed by water is antimony trichloride. 

385. Bromides. Eeadily soluble are the bromides of potas- 
sium, sodium, lithium, ammonium, barium, strontium, 
calcium, magnesium, zinc, aluminum and ferrous and ferric 
bromide. 

Soluble, though rather sparingly, are mercuric bromide 
and bromide of gold. 

Insoluble are the bromides of silver, lead, and mercurous 
bromide. 

386. Iodides. Freely soluble are the iodides of potassium, 
sodium, lithium, ammonium, barium, strontium, calcium, 



224 A CORRESPONDENCE COURSE IN PHARMACY 

magnesium, zinc, cadmium, ferrous iodide, manganous iodide 
and arsenous iodide. 

Insoluble are the iodides of silver, lead and mercury. 

387. Cyanides. Those of the alkali metals are freely 
soluble. Mercury cyanide is soluble. Silver cyanide is insol- 
uble. 

388. Ferrocyanides and Ferricyanides of the alkali metals 
are water-soluble. 

389. Sulphides. Those of the alkali metals and the 
alkaline earth metals are freely water-soluble. All sulphides 
of the heavy metals are insoluble. 

390. Hypochlorites of the alkali metals and alkaline earth 
metals are soluble. 

391. Chlorates of potassium and sodium are soluble. 

392. Sulphites of potassium and sodium are readily soluble. 
Those of calcium and magnesium are soluble. 

393. Sulphates. All metallic sulphates are soluble, except 
those of barium, strontium, calcium, lead and mercury. 
Readily soluble sulphates are those of sodium, ammonium, 
aluminum and ferric sulphate, also the alums. Soluble are 
the sulphates of potassium, lithium, magnesium, zinc, ferrous 
sulphate, manganous sulphate and copper sulphate. Very 
sparingly soluble is calcium sulphate. Insoluble are the 
sulphates of barium, strontium and lead. Decomposed by 
water is sulphate of mercury. 

394. Thio-sulphates of potassium and sodium are freely 
soluble. 

395. Sulphated potassa and sulphurated lime are freely 
soluble. 

396. Nitrates. All are water-soluble except those of 
mercury and bismuth, which are decomposed by water. 

397. Nitrites of the alkali metals are soluble. 

398. Phosphates, Pyrophosphates and Metaphosphates. 
The only water-soluble phosphates are those of potassium, 



SOLUBILITIES OF COMMON INORGANIC COMPOUNDS 225 

sodium and ammonium, but some phosphates of the heavy 
metals, also the phosphates of the alkaline earth metals and 
magnesium, are soluble in phosphoric acid. 

399. Orthophosphates of iron are soluble in orthophosphoric 
acid, but insoluble in pyrophosphoric or metaphosphoric 
acid. Pyrophosphates and metaphosphates of iron are 
insoluble in orthophosphoric acid, but soluble in meta- 
phosphoric acid. 

400. Hypophosphites. Those of the alkali metals and of 
calcium are water-soluble. Those of the heavy metals are 
insoluble, or .nearly so. 

401. Carbonates. The only water-soluble carbonates are 
those of potassium, sodium and ammonium. That of lithium 
is but sparingly soluble. 

402. Borates. Borax is soluble. 

403. Acetates of the metals are all water-soluble. 

404. Valerates. Those of potassium, sodium,, lithium and 
ammonium are soluble. Valerate of zinc is sparingly so. 

405. Oxalates. Only those of the alkali metals and ammo- 
nium are soluble. 

406. Tartrates. The normal tartrates of the alkali metals 
and ammonium are soluble. Their bitartrates are sparingly 
soluble. The tartrates of ferryl and potassium, and ferryl and 
ammonium, and antimonyl and potassium are soluble. 

407. Citrates. Those of the alkali metals, ammonium and 
iron are soluble. Magnesium citrate is soluble in water con- 
taining much citric acid. Bismuth citrate is insoluble, but 
citrate of bismuth and ammonium is soluble. 

408. Lactates of the alkali metals, calcium, strontium, 
magnesium, zinc and iron are water-soluble. 

409. Salicylates. Those of the alkali metals are alone 
water-soluble. 

410. Phenol Sulphonates. Those of the alkali metals and 
of barium, calcium and zinc are water-soluble. 



22G A CORRESPONDENCE COURSE IN" PHARMACY 

411. Benzoates. Those of the alkali metals and of ammo- 
nium and calcium are water-soluble. 

412. Oleates. Only the soaps are water-soluble. 

413. The student will find it very useful carefully to 
memorize the following: 

All of the officinal compounds of potassium, sodium and 
ammonium are water-soluble, but cream of tartar is only very 
sparingly soluble. 

The hydroxides of potassium, sodium and ammonium are 
freely soluble. 

The oxides, hydroxides, sulphides, carbonates, oxalates, 
phosphates (including pyrophosphates, metaphosphates and 
orthophosphates), hypophosphites, arsenates, arsenites, sali- 
cylates, benzoates and oleates of the heavy metals are all 
insoluble. 

ALCOHOL SOLUBILITIES 

414. A very large proportion of the inorganic chemical 
compounds are insoluble in alcohol, and especially those that 
contain much water. Inorganic chemical, compounds which 
are insoluble in water are also, with scarcely any exception, 
insoluble in alcohol, but even a large number of the water- 
soluble inorganic chemicals are insoluble in alcohol. 

415. Very soluble (in less than 5 parts of alcohol) are: 
Hydroxides of potassium, sodium and ammonium. 
Chlorides of magnesium, zinc, iron and mercuric chloride. 
Bromides of lithium, barium, strontium, calcium, mag- 
nesium and zinc. 

Iodides of lithium, sodium, barium, calcium, magnesium 
and zinc. 

Acetate of potassium. 

Valerates of potassium, sodium, ammonium and iron 
(ferric). 

Salicylates of potassium, sodium, lithium and ammonium. 

Ferric sulphate. 



SOLUBILITIES OV COMMON INORGANIC COMPOUNDS 227 

416. Soluble in from 6 to 30 parts of alcohol : 
Iodine, 1 in 10. 

Boric acid, 1 in 15. 

Chloride of lithium, 1 in 10; of strontium, 1 in 6; of 
calcium, 1 in 8. 

Bromide of sodium, 1 in 13; of ammonium, 1 in 30. 

Iodide of potassium, 1 in 18 ; of ammonium, 1 in 9. 

Mercuric cyanide, 1 in 15. 

Nitrate of ammonium, 1 in 20. 

Hypophosphite of potassium, 1 in 7.3; sodium, 1 in 30. 

Acetate of sodium, 1 in 30; lead, 1 in 21. 

Lactate of strontium. 

Benzoate of lithium, 1 in 12, and ammonium, 1 in 28. 

417. Sparingly soluble (in from 36 to 200 parts of alcohol): 
Bromide of potassium, 1 in 200. 

Iodide, mercuric, 1 in 130. 
Chlorate of sodium, 1 in 100. 
Nitrate of sodium, 1 in 100. 
Phenolsulphonate of sodium, 1 in 132. 
Acetate of zinc, 1 in 36. 
Valerate of zinc, 1 in 40. 
Benzoate of sodium, 1 in 45. 

418. Insoluble, or nearly so, in alcohol are: 

All metallic carbonates, oxalates, phosphates, pyro- 
phosphates, metaphosphates, arsenates, arsenites, citrates 
and tartrates. 

All metallic sulphates except ferric sulphate. 

All the scale-salts of iron. 

Chlorides of potassium, sodium and ammonium and 
mercurous chloride. 

Iodide of lead and mercurous iodide. 

Cyanide of potassium. 

Nitrates of potassium, lead, copper and mercury. 

Chlorate of potassium. 



228 A CORRESPONDENCE COURSE IN PHARMACY 

Nitrate of sodium. 

Sulphite of potassium. 

Thio-sulphate of sodium. 

Borax. 

Potassium dichromate. 

All the ferrocyanides and ferri cyanides. 

Ammoniated mercury. 

Ferrous lactate. 

Test Questions 

1. Write the chemical reaction which takes place when 
sodium is placed in water. 

2. What is the most common potassium compound with 
which you are acquainted ? Give the molecular formula for 
that compound. 

3. What is the difference between washing soda and bak- 
ing soda ? Give the molecular formulas of both. 

4. What is cream of tartar ? 

5. What is the color of sodium thio-sulphate ? 

6. What kind of a salt is Castile soap ? 

7. What is the percentage of bromine in potassium bro- 
mide and in lithium bromide ? 

8. Give the molecular formula of strontium sulphate. 

9. Give the molecular formula of barium hydroxide. 

10. Describe calcium. 

11. What is the difference between CaS0 4 + 2H 2 and 
CaH 4 S0 6 ? 

12. What is the difference between quick lime and slaked 
lime? 

13. What is chloride of lime ? 

14. What is talcum ? 

15. Give the molecular formula of magnesium hydroxide. 

16. What is the difference between MgS0 4 + H 2 and 
MgH 2 S0 5 ? 



SOLUBILITIES OF COMMON INORGANIC COMPOUNDS 229 

17. What kind of a sulphate is MgS0 4 and what kind of 
a sulphate is MgH 2 S0 5 ? 

18. How many aluminum atoms are contained in 
3NaF.ALF 3 ? 

19. How many different systems of atomic linking do you 
find in the foregoing formula ? 

20. What is the molecular formula for alum ? 

21. Write the molecular formula for aluminum and sodium 
sulphate. 

22. What is the most common source of aluminum ? 

23. Can you mention any property by which the light 
metals differ chemically from the heavy metals ? 

24. What is zinc blende ? 

25. What is formed when zinc is dissolved in diluted sul- 
phuric acid ? Write the reaction. 

26. What is formed when zinc is dissolved in so-called 
hydrochloric acid ? Write the reaction. 

27. What is the difference between ferrous phosphate and 
ferric phosphate ? 

28. What is the difference in color between a solution 
of ferric chloride and a solution of ferrous chloride ? 

29. Can you trace the atomic linking in the substance 
represented as Fe 3 4 ? 

30. What is the difference between FeO + Fe 2 3 and 
Fe 2 Fe0 4 ? 

31. What is FeH 2 S0 5 ? 

32. WhatisFe(N0 3 ) 2 ? 

33. What is Fe(N0 3 ) 3 ? 

34. What is FeO ? 

35. What is the algebraic combining number of each of 
the two elements in nickelic arsenide ? 

36. What is the difference between chromic anhydride and 
chromic acid ? Write the molecular formulas for both. 

37. What is the difference between potassium dichromate 



230 A CORRESPONDENCE COURSE IN PHARMACY 

and potassium bichromate ? Write the molecular formulas 
for both. 

38. WhatisMn0 2 ? 

39. If such a compound as MnMn0 4 exists, what is it, and 
how does it differ from Mn0 2 ? 

40. What is the difference between basic manganese and 
acidic manganese as to valence ? 

41. What is galena ? 

42. What is Pb0 2 ? 

43. Can you trace the atomic linking in Pb 3 4 ? 

44. Can you trace the atomic linking in Pb 2 Pb0 4 ? 

45. If Pb 2 Pb0 4 exists, what is its technical title ? 

46. What is the highest valence possible to lead, as 
indicated by its position in the periodic system ? 

47. Give the molecular formula for sulphate of copper. 

48. What are the differences between mercurous com- 
pounds and mercuric compounds ? 

49. How can you distinguish between them when you see 
their molecular formulas ? 

50. How is mercury obtained ? 

51. What is the difference between calomel and corrosive 
sublimate ? 

52. Silver nitrate being soluble in water, how would you 
make it ? 

53. Silver chloride being insoluble in water, how would 
you make it ? 

54. What is the combining value of silver ? 

55. Why is it that aqua regia dissolves gold but does not 
dissolve silver ? 

56. What is the algebraic combining number of the 
bismuth in OBiCl ? 

57. Write the formula for bismuthic oxide. 

58. Write the formula for bismuthous sulphide. 

59. Write the formula for stannic chloride. 



LESSON SIXTEEN 

XXV 

Weights and Measures 

419. Three different systems of weights and measures are 
at the present time in use in medicine and pharmacy, 
although the metric system is exclusively employed in all 
pharmacopoeias except the British, and the British phar- 
macopoeia uses both the metric system and the imperial 
system. 

Physicians who write prescriptions employ the metric 
system exclusively in all countries except Great Britain and 
America. In Great Britain they use partly the imperial 
system and partly the old apothecaries' system, while in the 
United States the apothecaries' system is generally used. 
Pharmacists in this country must therefore understand all 
the three systems — the imperial system, the apothecaries' 
system and the metric system. It is also necessary that 
pharmaceutical students understand the relations of weight 
and volume to each other and the principles of metrology. 

420. The metric system is the most scientific and simple 
system of weights and measures in use. 

Its chief merit is that it is decimal, and therefore in perfect 
harmony with our arithmetical notation. We count from 
1 to 10 and the number 10 is expressed by two numerals. 
When we reach 100 we use three numerals, and for 1000 
we use four. In other words, the periodic number of our 
arithmetic is 10. 

231 



232 A CORRESPONDENCE COURSE IN PHARMACY 

No mathematician believes that 10 is the most convenient 
periodic number; on the contrary, either 8 or 12 would be 
far superior to 10, because 8 can be subdivided successively 
by 2 until unity is reached, and, moreover, the number 8 
contains the cube of the smallest number that can be cubed. 
It is evidently most natural to men to divide numbers into 
halves and quarters, eighths, sixteenths, thirty-seconds, etc. 
It is not natural to divide by 10 and 5. The number 12 can 
be divided by either 6, 4, 3 or 2, but cannot be divided 
successively by 2 without striking fractions. Hence, although 
12 is preferable to 10, it is probably not so convenient as 8. 

The only reason advanced against the introduction of the 
metric system which has any weight or deserves any atten- 
tion is the argument that our system of arithmetic is 
unnatural and will probably be changed in the course of 
time; but it has been admitted by those who advance this 
argument against the metric system that probably centuries 
will elapse before a more natural system of arithmetical 
notation is adopted. Every one competent to express an 
opinion will readily admit that whatever our system of 
arithmetic may be, our weights, measures and money ought 
to agree with it. Since, therefore, our arithmetical notation 
is decimal, it follows that our weights, measures and money 
should also be decimal, in order that computations may be 
rendered as simple as possible; and if we are going to continue 
to use decimal arithmetic for centuries, we certainly should 
in the meantime use decimal weights, measures and money 
instead of waiting for reform in weights and measures until 
a new system of arithmetic has been introduced. 

421. The metric system was devised a little over one 
hundred years ago. Many of the world's scientific men were 
concerned in constructing it. It was first decided that it 
should be decimal. Next, it was decided that it should be 
based upon some linear unit, and that measures of surface, 



WEIGHTS AND MEASURES 233 

volume and weight should be based upon the linear unit 
primarily. 

Next, it was decided that the linear unit chosen should be 
an aliquot part of some physical constant. The physical 
constants that have been thought of are the length of the 
polar axis, the length of the equator and the length of the 
meridian, also the length of the seconds pendulum — a pen- 
dulum of such length that it swings in seconds of time at a 
given latitude — or the length of the seconds rod, which is 
exactly 50 per cent longer than the seconds pendulum. The 
idea involved in the selection of a physical constant as the 
natural basis of a universal system of weights and measures 
was that the dimensions and movements of the earth can be 
measured at any time, so that if the material standard made 
to represent the natural standard should ever be lost, it could 
be replaced with absolute certainty of perfect sameness. In 
devising the metric system, the length of the meridian was 
chosen as the primary natural standard, and the length of 
the seconds pendulum was chosen as a secondary standard to 
serve as a check upon the other. But the length of the 
seconds pendulum is hardly ever mentioned in connection 
with the metric system any longer, and the length of the 
meridian has now but a theoretical and sentimental connec- 
tion with the metric system based upon the meter. The 
original meter was intended to be identical with the forty- 
millionth part of the length of the meridian, or the ten- 
millionth part of the quadrant, and in order to arrive at this 
unit of length an arc of the meridian was measured from 
Dunkirk to Barcelona, and a platinum bar was constructed 
and called the meter. Upon the length of this meter the 
whole metric system was based. It has since been held by 
some that the platinum meter is not exactly identical with 
the ten-millionth part of the quadrant. At all events, the 
question is a disputed one. 



234 A CORRESPONDENCE COURSE IN PHARMACY 

Whether the theoretical meter, which is the forty-millionth 
part of the meridian, and the actual meter made of platinum 
are identical is of no consequence whatever, for there are 
now extant in the world a large number of meter bars made 
of platinum alloyed with 10 per cent of iridium which are 
microscopically accurate, and as these several meter bars are 
kept in various parts of the world and are so constructed 
that they will resist any injury, we shall never lose all of 
them. Any meter bar lost can be readily replaced with the 
absolute certainty that the new one will have precisely the 
same value as the one lost. Hence, there will never be any 
occasion for measuring the meridian again for the purpose 
of constructing a new meter bar. 

422. The original platinum meter is preserved in the 
archives of France, and is universally called the " Metre des 
Archives." It is believed to be porous and inferior in other 
ways to the irido-platinum meter bars now used, so that the 
Metre des Archives is merely an interesting historical relic. 
It is never used. 

423. The modern meter bars are constructed by the Inter- 
national Metric Bureau, an institution established by the 
civilized nations of the world, who all contribute toward its 
maintenance. The International Metric Bureau is located 
near Paris. It has supplied standard meter bars and stand- 
ard kilogram weights to all countries, and is engaged in 
investigations and scientific, determinations connected with 
weights and measures for the benefit of the civilized world. 

424. The units employed in the metric system for the 
measurement of surfaces are simply the squares upon the 
meter and upon decimal multiples and subdivisions of the 
meter. For the measurement of bulk the cubes upon the 
meter and its decimal multiples and subdivisions are used. 
In order to obtain a unit of mass, the scientific men who 
devised the metric system decided that the mass of a given 



WEIGHTS AKD MEASUEES 235 

volume of water at the temperature of the maximum density 
of that liquid should constitute that unit. Hence, the 
weight of a cubic centimeter of water at 4° C, weighed in 
vacuo, was called a gram, and that gram is the unit of 
weight of the metric system. In France there is, further, a 
simple relationship between the metric unit of weight and 
the weight of the silver coinage. 

425. The important units of the metric system for the 
measurement of linear measure, square measure, cubic 
measure and weight are the meter, the are, the stere, the 
liter and the gram; the meter for long measure, the are for 
land measure, the stere for the measurement of large bulks, 
the liter, or cubic decimeter, for capacity measure for 
smaller volumes, and for weight the gram, and one thousand 
grams make the so-called kilogram represented by the mass 
standards of metric countries. 

426. One of the defects of the metric system is the 
redundance of units it provides. A new unit with a new 
name has been provided for each successive decimal multiple 
and for each successive decimal subdivision of each of the 
principal units. 

The multiples are indicated by Greek prefixes; namely, the 
word deka, which means ten; the word liehto, which means 
one hundred; fcilo, which means one thousand; and myria, 
which means ten thousand. A dekagram, therefore, means 
a ten-gram, and hektometer means a one-hundred-meter; 
three kiloliters means three thousand-liters, and a myria- 
gram means one ten-thousand-gram. 

The subdivisions are named with the aid of Latin prefixes ; 
namely, deci, which means one-tenth; centi, which means 
the one-hundredth part; and milli, which means a one- 
thousandth. A milliliter, therefore, is a one-thousandth- 
liter; a centigram is a one-hundredth-gram, and a decimeter 
is .a one-tenth-meter. 



236 A CORRESPONDENCE COURSE IN" PHARMACY 

It is not only unnecessary but burdensome to use so many 
different units. The superfluity of these many units is well 
exemplified by the following illustration : In America the 
monetary unit is called the dollar. In common speech we 
speak of ten dollars as an eagle, of the tenth of a dollar as a 
dime, the one-hundredth part of a dollar as a cent, and the 
one-thousandth part of the dollar as a mill. But no sensible 
person would count money in eagles, dollars, dime's, cents 
and mills. We find the dollar and the cent amply sufficient 
for all purposes. 

In the metric system the only necessary linear units are 
the kilometer, the meter and the millimeter. For capacity 
measures the liter and the milliliter are sufficient, and for 
weights, the kilogram, the gram and the milligram. 

427. The following tables of the weights and measures of 
the metric system are sufficient for purposes of study: 



Linear 


Measure 


1 kilometer = 


1,000 meters 


1 hektometer = 


100 meters 


1 dekameter = 


10 meters 


1 meter = 


1 meter 


1 decimeter = 


0.1 meter 


1 centimeter = 


0.01 meter 


1 millimeter = 


0.001 meter 



1 meter is equal to 39.37 inches, and 25 millimeters nearly equal 
inch. 

Square Measure 
1 square kilometer = 1,000,000 square meters 
1 square meter = 100 square decimeters 

1 square meter = 10,000 square centimeters 

1 square meter = 1,000,000 square millimeters 

Land Measure 
1 square meter is called a centiare 
100 square meters is an are 
10,000 square meters is a hektare. 



WEIGHTS AND MEASURES 237 

Cubic Measure 



1 cubic meter 


= 1,000 cubic decimeters 


1 cubic decimeter 


= 1 ,000 cubic centimeters 


The cubic meter is called a 


Stere. 


Capacity Measures 


1 kiloliter 


= 1,000 liters 


1 hektoliter 


= 100 liters 


1 dekaliter 


= 10 liters 


1 liter 


= 1 cubic decimeter 


1 deciliter 


= 0.1 liter 


1 centiliter 


= 0.01 liter 


1 milliliter 


0.001 liter 


One liter is equivalent to about 33.8 U. S. fluid ounces. 


Weight Units 


1 kilogram 


= 1,000 grams 


1 hektogram 


= 100 grams 


1 dekagram 


= 10 grams 


1 gram 


= 1 gram 


1 decigram 


= 0.1 gram 


1 centigram 


= 0.01 gram 


1 milligram 


= 0.001 gram 



One gram is equivalent to 15.432 grains (nearly). 

428. The system of weights and measures in the United 
States is an incongruous mixture of old standards which 
were introduced into this country during colonial times. 
Several of the units we employ have been abolished in Great 
Britain, and the values of our customary weights and 
measures are probably not absolutely identical with the 
original English values, which they are supposed to represent. 

Our linear units are squared and cubed, but our unit of 
land measure, the acre, does not bear a simple relationship 
to the standard yard ; nor do the bushel and gallon measures 
bear a simple relationship either to the yard or the pound. 
We have several kinds of gallons and several kinds of pounds, 
although only two of the gallons are actually used. 

429. The original theoretical yard was of such length that 
the length of the seconds pendulum at Greenwich, England, 



238 A CORRESPONDENCE COURSE IN PHARMACY 

was expressed by 39.1393 inches, each inch being the thirty- 
sixth part of the standard yard; but it is not absolutely 
certain that either the British yard or the American yard is 
now identical with the value just stated, for when the original 
British standard yard was lost and a commission was ap- 
pointed to remeasure the length of the seconds pendulum 
and to construct a new standard yard from the results, the 
task was abandoned as impracticable and an extant copy of 
the old standard yard was chosen and adopted as the new 
standard, and in our country the length of the yard is now 
!$£$ °f the length of the meter. The present American 
yard may or may not be absolutely identical with the present 
British yard. 

430. Our customary capacity measures are not based upon 
the linear unit, but upon weight. Our bushel measures, 
gallon measures and their subdivisions are, in other words, 
constructed and verified by weight. Originally the gallon 
employed for the measurement of liquids (the Old English 
wine gallon) was 231 cubic inches, but the American gallon 
of to-day is the volume of 3785.434 grams of water at 4° 0., 
weighed in vacuo. Whether or not that volume is 231 cubic 
inches is doubtful. 

The National Bureau of Standards of America adjusts the 
liquid gallon by weight, on the assumption that 252.892 
grains of water at its maximum density, weighed in vacuo , 
measures one cubic inch. If the theoretical kilogram, which 
is the weight of one cubic decimeter of water at its maximum 
density in vacuo, is identical with the actual international 
standard kilogram, which is assumed to be equivalent to 
15432. 35G39 grains, then, as 39.37 inches is equal to one 
meter, the weight of a cubic inch of water at its maximum 
density in vacuo is 252.892 grains, and from this value the 
weight of 231 cubic inches of water at its maximum density 
in vacuo must be 3785.434 grams. But many authorities 



WEIGHTS AND MEASURES 239 

declare that the weight of one cubic inch of water at its 
maximum density, weighed in vacuo, is not 252.892 grains. 
If so, onr liquid gallon is not 231 cubic inches. 

The gallon for dry measure in America is supposed to be 
the old English Winchester gallon of 268 cubic inches. 

431. The commercial pound of this country is assumed to 
be identical with the British imperial pound, but we also 
employ in America the old English Troy pound, and a copy 
of the old British Troy pound is kept in the custody of the 
United States Mint at Philadelphia for the purpose of regu- 
lating the coinage of the United States, in accordance with a 
resolution of Congress. The Troy weight is used also for 
weighing gold and silver bullion, gold and silver ware and 
jewelry. 

The Troy pound is subdivided into 12 Troy ounces, and 
each Troy ounce is subdivided into 20 pennyweights, and 
each pennyweight into 24 grains. It will be seen, there- 
fore, that the subdivisions of the Troy pound are not identical 
with the subdivisions of the commercial pound, called the 
avoirdupois pound, nor is it identical with the subdivision 
of the apothecaries' pound. 

The value of the Troy ounce is not identical with the value 
of the avoirdupois ounce, but it is identical with the value 
of the apothecaries' or medicinal ounce. The only unit of 
avoirdupois weight, Troy weight and apothecaries' weight 
having the same value is the grain. 

432. The customary weights and measures of America are 
as follows : 

Linear Measure 

1 league = 3 miles, or 5,280 yards 

1 mile = 8 furlongs, or 1,760 yards 

1 furlong = 40 poles or rods 

1 pole or rod = 5 \ yards 

1 yard = 3 feet, or 36 inches 

1 foot =12 inches 



240 A CORRESPONDENCE COURSE IN PHARMACY 

Surface Measure 

1 square mile = 640 acres 

1 acre = 4 roods, or 4,840 square yards 

1 rood = 40 square poles 

1 square pole= 30 \ square yards 
1 square yard = 9 square feet 

1 square foot = 144 square inches 

Cubic Measure 
1 cubic yard = 27 cubic feet 
1 cubic foot = 1,728 cubic inches 

Capacity Measure 
Dry "Measures 
1 bushel = 4 pecks, or 32 dry quarts 

1 peck = 2 dry gallons, or 8 dry quarts 

1 dry gallon = 4 dry quarts, or 8 dry pints 
1 dry quart = 2 dry pints 

Liquid Measures 

1 liquid gallon (wine gallon) = 4 liquid quarts 

1 liquid quart = 2 liquid pints 

1 liquid pint = 4 gills 

American Medicinal Fluid Measures 
1 liquid gallon = 4 liquid quarts 
1 quart = 2 pints 

1 pint = 16 fluid ounces 

1 fluid ounce = 8 fluid drams 
1 fluid dram = 60 minims 

Weights 
Commercial or Avoirdupois Weights 
1 ton = 20 hundredweights, or 2,000 pounds 

1 hundredweight =100 pounds 
1 pound = 16 ounces, or 7,000 grains 

1 ounce = 16 drams, or 437£ grains 

1 dram (now obsolete) = 27£$ grains 

Troy Weights 
1 troy pound = 12 troy ounces, or 5,760 grains 

1 troy ounce = 20 pennyweights, or 480 grains 

1 pennyweight = 24 grains 



WEIGHTS AND MEASURES 241 

Apothecaries' Weights 
1 pound = 12 ounces, or 5,760 grains 
1 ounce = 8 drams, or 480 grains 
1 dram = 3 scruples, or 60 grains 

1 scruple = 20 grains 

433. The imperial system of Great Britain was adopted 
in 1824, to take effect January 1, 1825. 

The imperial gallon is the volume of 10 imperial pounds 
of pure water at 62° F., weighed in air of the same tempera- 
ture. Therefore the imperial gallon is based upon weight and 
not upon any linear unit. It is true that the British Par- 
liament has also declared that the imperial gallon is equal to 
277.274 cubic inches, but the volume of 10 pounds of water 
under the British standard conditions must depend upon 
natural laws, without reference to legislation by Parliament. 
If 277.274 cubic inches of water at 62° F., weighed in air, 
does not weigh 10 pounds, Parliament cannot alter the fact. 

As the British pound is subdivided into 7000 grains and 
into 16 ounces, each equivalent to 437.5 grains, and as the 
imperial gallon is subdivided into 8 pints, and each pint 
into 20 fluid ounces, it follows that the imperial weight 
ounce and the imperial fluid ounce are commensurate units, 
with regard to water, under the British standard conditions. 
In other words, an imperial fluid, ounce of water weighs 
one imperial ounce, or one imperial ounce of water measures 
an imperial fluid ounce. But the imperial minim of water 
does not weigh one grain. 

434. The capacity measures of the imperial system are 
shown in the following table : 

1 bushel = 4 pecks, or 32 quarts 

1 peck = 2 gallons, or 8 quarts 

1 gallon = 4 quarts, or 8 pints, or 160 fluid ounces 

1 quart = 2 pints, or 40 fluid ounces 

1 pint = 20 fluid ounces 

1 fluid ounce = 8 fluid drams 

1 fluid dram — 60 minims 



242 A CORRESPONDENCE COURSE IN PHARMACY 

435. The linear measure of the British imperial system 
is the same as prior to 1825 and practically identical with 
the American customary long measure. The surface 
measures are the same as those used in this country The 
only weights which may be legally used in Great Britain are 
the avoirdupois weights, and the only liquid measures are the 
imperial measures referred to in the preceding paragraph. 

436. From the foregoing, the student will see that the 
theoretical meter is the forty-millionth part of the length of 
the meridian, while the actual meter is the length of the 
material prototype meter of the International Metric Bureau. 

The theoretical liter is one cubic decimeter, but the actual 
liter is the volume of one kilogram of water at 4° C, weighed 
in vacuo, because capacity measures must of necessity be 
constructed by and based upon weight and not upon linear 
measure. 

The theoretical kilogram is the mass of one cubic decimeter 
of water at 4° C, but the actual kilogram is the mass of the 
piece of irido-platinum of the International Metric Bureau, 
called the standard kilogram. 

The standard kilogram of the International Metric Bureau 
is probably too light. In other words, the true mass of one 
cubic decimeter of water at 4° 0. is probably more than one 
standard kilogram. 

437. In the metric system the liter is subdivided into 1000 
milliliters, but the milliliter is very generally referred to as 
a cubic centimeter, and in tables of weights and measures it 
is stated that one liter is equivalent to 1000 cubic centimeters. 
But the student should observe that the one-thousandth part 
of one cubic decimeter, which is of course one cubic centi- 
meter, cannot be one milliliter unless the liter is exactly 
equivalent to one cubic decimeter. The actual liter in use 
is the volume of one kilogram of water at 4° C, weighed in 
vacuo, and as the kilogram upon which the liter is based 



WEIGHTS AND MEASURES 243 

and by which it is standarded cannot be the theoretical kilo- 
gram but is instead the actnal kilogram, which is too light, 
the actual liter must be less than one cubic decimeter. 

438. The relations between the various units of weight 
and measure in use by civilized nations are shown in the 
following tables : 

Long Measure 

1 league = 4,828 meters 

1 mile = 1,609.3 meters 

1 furlong =» 201.2 meters 

1 rod = 5.03 meters 

1 yard = 36 inches = 0.914 meters 

1 foot = 30.48 centimeters 

1 inch = 25.4 millimeters 

1 kilometer = 0.6213 mile 

1 meter = 1.0936 yards 

1 meter = 3.28 feet 

1 meter = 39.37 inches 

Surface Measure 
1 square mile = 259 hektares 
1 acre =40.47 square meters 

1 square yard = 0.8361 square meter 
1 square foot = 9.29 square decimeters 
1 square inch = 6.452 square centimeters 

1 square meter = 1.196 square yards 
1 square meter = 10.764 square feet 
1 hektare = 2.471 acres 

Measures of Capacity 
1 bushel = 35.24 liters 

1 peck = 8.81 liters 

1 dry gallon = 4.40 liters 

1 dry quart = 1.10 liters 

1 American liquid gallon = 3,785.4 liters 
1 American liquid quart = 0.946 liter 
1 American liquid pint = 473 milliliters 



244 



A CORRESPONDENCE COURSE IN PHARMACY 



1 American fluid ounce 
1 American fluid dram 
1 American minim 



29.57 milliliters 
3.697 milliliters 
0.0616 milliliter 



1 British Imperial gallon 
1 British Imperial quart 
1 British Imperial pint 

1 British Imperial fluid ounce 
1 British Imperial fluid dram 
1 British Imperial minim 

1 American liquid gallon 
1 American liquid quart 
1 American liquid pint 

1 American fluid ounce 
1 American fluid ounce 

1 British Imperial gallon 
1 British Imperial gallon 
1 British Imperial pint 

1 British Imperial fluid ounce 
1 British Imperial fluid ounce 



4.543 liters 
1.136 liters 
0.568 liter 

28.39 milliliters 
3.55 milliliters 
0.059 milliliter 

0.833 British Imperial gallon 
0.833 British Imperial quart 
0.833 British Imperial pint 

1.04 British Imper'l fluid ounces 
500 British Imperial minims 

1.200 American liquid gallons 
9.601 American liquid pints 
1.200 American liquid pints 



0.96 
461 



American fluid ounce 
American minims 



1 liter = 0.2642 American liquid gallon 
1 liter = 1.0567 American liquid quarts 
1 liter = 33.81 American fluid ounces 

1 liter = 0.220 British Imperial gallon 
1 liter = 0.881 British Imperial quart 
1 liter = 35.23 British Imperial fluid ounces 

Measures of Weight 
1 kilogram = 2.205 avoirdupois pounds 
1 gram = 15.432 grains 

1 milligram = g 1 ^ grain 

1 avoirdupois pound = 453.6 grams 
1 avoirdupois ounce = 28.35 grams 
1 grain = 64.8 milligrams 



WEIGHTS AND MEASURES 245 

1 American medicinal pound = 373.243 grams 
1 American medicinal ounce = 31.10 grams 

1 avoirdupois pound = 1.215 Troy pounds 

1 avoirdupois ounce = 0.911 American medicinal ounce 

1 American medicinal pound = 0.823 avoirdupois pound 
1 American medicinal ounce = 1.097 avoirdupois ounces 

Convenient Approximate Equivalents 
1 kilogram =32 medicinal ounces 
1 milligram = -^ grain 

1 grain = 64 milligrams 

480 American minims = 500 Imperial minims 

The weight of 96 American medicinal fluid ounces of water is 100 
avoirdupois ounces. 

439. The differences between the values of the theoretical 
and the actual units of the metric system and the differences 
between the actual and theoretical values of some of the 
customary units of weights and measures are so insignificant 
that in actual practice they are ignored. In fact, it is 
sufficient in all ordinary operations to employ approximate 
equivalents. For example, it is sufficient to consider one 
meter as equivalent to 40 inches and one inch as equivalent 
to 25 millimeters. It is quite sufficient to consider one liter 
as equivalent to 34 apothecaries' fluid ounces. It is even 
perfectly allowable to consider one apothecaries' fluid ounce 
as equivalent to 32 cubic centimeters, although it is more 
nearly 30 cubic centimeters. If one fluid ounce be con- 
sidered as equivalent to 32 cubic centimeters, then one fluid 
dram is equivalent to 4 cubic centimeters, and one cubic 
centimeter is equivalent to 15 American minims. It is 
sufficient to consider one apothecaries' ounce as equivalent 
to 32 grams, although it is a little over 31 grams. If the 




240 A CORRESPONDENCE COURSE IN PHARMACY 

apothecaries' ounce be considered as equivalent to 32 grams, 
then one dram is equivalent to 4 grams, and one gram is 
equivalent to 15 grains. But in the pharmaceutical labora- 
tory and at the dispensing table it matters little 
whether one gram be considered equivalent to 
15 grains or 15.432 grains or 16 grains, and it 
is immaterial whether the cubic centimeter be 
considered as equivalent to 15 minims or 16 min- 
ims. It makes no difference whether a certain 
amount of medicine be divided into 31 equal 
doses or into 32 equal parts, for a dose of medi- 
glass meas- cine of any kind is of necessity an arbitrary one, 
representing simply the best judgment of the 
medical man in each instance. It would be impossible to 
observe any difference between the medicinal action of 30 
grains and the medicinal action of 31 grains of the same 
substance. In chemical analysis the conditions are of course 
altogether different. The most accurate balances and weights 
are necessary in chemical determinations, while in the weigh- 
ings at the dispensing table a balance sensitive to two or 
three milligrams is sufficient, and more durable than a bal- 
ance sensitive to the fraction of one milligram. 

Thirty-two Troy ounces or apothecaries' ounces of water 
at ordinary room temperatures is equal to one liter, and 32 
apothecaries' ounces is equal to one kilogram. One grain 
is equal to 64 milligrams, or, in other words, ^ of a grain 
is equal to one milligram. As 6 American liquid pints of 
water weighs 100 avoirdupois ounces, it follows that the 
weight of 6 pints of anything else in avoirdupois ounces must 
be 100 times its specific gravity. 

To convert any number of kilograms into the correspond- 
ing number of avoirdupois pounds, multiply by 2.2. To find 
the weight in grams of any number of cubic centimeters, 
multiply the cubic centimeters by the specific weight. To 



WEIGHTS AND MEASURES 247 

find the volume in cubic centimeters of any number of grams, 
divide by the specific weight or multiply by the specific 
volume. To find the volume of any number of apothecaries' 
ounces in American fluid ounces, divide by the specific 
weight, or multiply by the specific volume, and then add 5 
pei cent. To find the weight in apothecaries' ounces of any 
number of fluid ounces of any liquid, multiply by the specific 
weight and deduct 5 per cent. This is because one fluid 
ounce of water weighs .95 of an ounce. 

Test Questions 

1. In what countries are the weights and measures of the 
imperial system used ? 

2. In what countries are the weights and measures of the 
apothecaries' system used ? 

3. In what countries is the metric system employed ? 

4. Why is a decimal system of weights and measures pref- 
erable to any other ? 

5. What was the object of making the length of the 
meridian the basis of the metric system ? 

6. What is the length of the quadrant ? 

7. What is the difference between the theoretical meter 
and the actual meter ? 

8. What is the difference between the theoretical liter 
and the actual liter ? 

9. What is the difference between the theoretical kilogram 
and the actual kilogram ? 

10. Where are all the standard prototypes of weights and 
measures made and adjusted ? 

11. How is the permanent loss of the metric standards 
prevented ? 

12. How many cubic millimeters are contained in one 
cubic decimeter ? 



248 A CORRESPONDENCE COURSE IN PHARMACY 

13. How many cubic centimeters in one cubic meter ? 

14. How many square centimeters in one square decimeter ? 

15. Do you know any other name for the cubic centimeter ? 

16. Do you know any other name for the liter ? 

17. What is a myriameter ? 

18. What is a decigram ? 

19. What one name is given to ten liters ? to one hundred 
grams ? to one thousand liters ? to the tenth of a gram ? to 
the hundredth part of a liter ? to the thousandth part of a 
kilogram ? to the thousandth part of a gram ? 

20. What is the difference between a milliliter and a cubic 
centimeter ? 

21. What is the difference between a liter and a cubic 
decimeter ? 

22. What is the exact value of the American yard ? 

23. What is the exact value of the wine gallon now in use 
for commercial purposes ? 

24. Is any other gallon used for commercial purposes than 
the wine gallon ? 

25. What is the difference between the old English wine 
gallon and the American wine gallon ? 

26. What is the ultimate standard for the adjustment of 
our bushel measures and gallon measures in America ? 

27. What is the ultimate standard which fixes the present 
value or size of an acre ? 

28. What is the weight of a cubic inch of water at 4° 0. 
in vacuo , according to the Government authorities of the 
United States ? 

29. What is the difference between a Troy ounce and an 
apothecaries' ounce ? 

30. What is the difference between an avoirdupois ounce 
and an imperial ounce ? 

31. What is the difference between an apothecaries' grain 
and an imperial grain ? 



WEIGHTS AND MEASUEES 249 

32. What is an imperial gallon ? 

33. What is the origin of the American liquid gallon ? 

34. Has the American liquid gallon ever been used in any- 
other country, and is it now in use in any other country ? 

35. What is the volume of ten pounds of water at 62° F. 
in air, measured in cubic inches ? 

36. What is the equivalent of the apothecaries' pound in 
grains ? 

37. What is the equivalent of the English commercial 
pound in grains ? 

38. Into how many drams is the Troy ounce subdivided, 
and into how many scruples is the Troy dram divided ? 

39. How many drams are there in an avoirdupois ounce ? 

40. Which has. the greater mass, the actual kilogram or 
the theoretical kilogram ? 

41. Which is greater, the actual liter or the theoretical 
liter ? 

42. What is approximately the equivalent of one kilogram 
in apothecaries' ounces ? 

43. How many milligrams equal one-half grain ? 

44. How many grams approximately equal one dram ? 

45. If you had a prescription for one powder with the 
quantities of the ingredients for that powder stated in grains, 
how would you convert that prescription into metric terms 
and increase the quantities so that fifteen powders can be 
made, each containing the same dose as in the original pre- 
scription ? 

46. An average adult dose of opium is considered to be 
one grain. What would it be set down to be in an ordinary 
dose table if our grain were 10 per cent larger than it is, 
and how much would it be set down to be if our grain were 
10 per cent lighter than it is ? 

47. What is the equivalent of two American fluid ounces 
in British minims ? 



250 A CORRESPONDENCE COURSE IN PHARMACY 

48. What is the weight of one quart of a liquid having the 
specific weight 1.800 ? 

49. What is the equivalent of an American fluid ounce in 
cubic centimeters and what is its equivalent in milliliters ? 

50. Which is larger, an imperial pint or an American pint ? 

51. Which is larger, an imperial fluid ounce or an Ameri- 
can fluid ounce ? 

52. Which is larger, an imperial minim or an American 
minim ? 

53. Which is larger, an imperial grain or an American 
grain ? 

54. What is the ultimate standard by which the weight 
of American coins is regulated ? 



LESSON SEVENTEEN 

XXVI 

Specific "Weight and Specific "Volume 

440. The specific weight of any substance is the relation 
of its mass to its volume. 

A substance having great weight in proportion to its 
volume is said to have a large specific weight, and a substance 
of which the same volume weighs less has a smaller specific 
weight. 

The specific weight of different substances must be con- 
veniently and intelligently expressed, and this is accomplished 
by stating specific weights in numbers referring to the 
specific weight of water as the unit. In other words, the 
relation of the weight of water to its volume under standard 
conditions is arbitrarily called 1, and the specific weight of 
any substance a given volume of which is heavier than the 
same volume of water is expressed by a number greater than 
1, while the specific weight of any substance a given volume 
of which weighs less than the same volume of water is 
expressed by a number less than 1. The number expressing 
the specific weight of any solid or liquid is the number of 
times the weight of that solid or liquid contains the weight 
of the same volume of water. In other words, it is ex- 
pressed by the number obtained by dividing the weight 
of a given volume of that solid or liquid by the weight 
of the same volume of water expressed in the same kind 
of weight units. The specific weight of chloroform is 

251 



252 A CORRESPONDENCE COURSE IN PHARMACY 

1.5, because a liter of chloroform weighs 1.5 kilograms; and 
the specific weight of ether of a certain strength is .750 if 
1000 cubic centimeters of it weighs 750 grams, for 1000 cubic 
centimeters of water weighs 1000 grams, and 750 -*■ 1000 is 
.750. 

In the pharmacopoeia and most of the technical works 
specific weights are expressed to the third decimal. Hence, 
the specific weight of chloroform is given as 1.500 and not 
as 1.5. 

441. Specific volume is the relation of the volume of a sub- 
stance to its mass. Accordingly, the specific volume of any 
substance is expressed by a number which is the reciprocal 
of the number expressing its specific weight. In other words, 
if the specific weight is 2, the specific volume must be -J. 
If the specific weight is f, the specific volume must be |. If 
the specific volume of any substance is |, then the specific 
weight must be J . 

Specific weights and specific volumes, when expressed by 
numbers with fractions, are expressed decimally, but if the 
specific weight is expressed by a common fraction, then the 
corresponding specific volume is found by simply inverting 
the fraction. For example, as the specific weight of chloro- 
form is 1.500, or stated in the form of a common fraction, 
io£o> ^ follows that the specific volume of chloroform is 
•TTnrij. As the specific weight of glycerin is 1.250, its specific 
volume must be 0.800, for 1.250 multiplied by 0.800 gives 
the product 1. The specific volume is found from the 
specific weight by dividing 1 by the specific weight, and the 
specific weight can be found from the specific volume by 
dividing 1 by the specific volume. 

The specific volume of any liquid is found also by dividing 
the volume of a given weight of the liquid by the volume of 
the same weight of water, expressed in the same units. 

The use of the term specific volume to indicate the relation 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 253 

of the volume of a liquid to its weight as here explained was 
first proposed by the writer of this book in 1883. Its 
practical value depends upon the fact that multiplication is 
an easier operation than division. In converting weight into 
volume we multiply the weight by the specific volume, if the 
weight units and the volume units are commensurate. 

442. Several pairs of commensurate units exist. The 
avoirdupois ounce and the imperial fluid ounce are commen- 
surate, because an avoirdupois ounce of water measures an 
imperial fluid ounce. The gram and the cubic centimeter 
are commensurate units, because a cubic centimeter of water 
weighs a gram ; and the liter and the kilogram are com- 
mensurate, because the liter is the volume of a kilogram of 
water. A kilogram of any liquid having the specific volume 
0.800 must measure 800 cubic centimeters. 

As 6 wine pints of water weighs 100 avoirdupois ounces, 
it follows that 96 American fluid ounces of any liquid having 
the specific weight 0.960 must weigh 96 fluid ounces. The 
specific weight of castor oil is 0.960; hence an American 
fluid ounce of it weighs one avoirdupois ounce. 

443. How the Specific Weight is Found. As the specific 
weight of any solid or liquid is the number of times the 
weight of a given volume of water is contained in the weight 
of the same volume of the solid or liquid, it follows that a 
simple method of finding the value sought is to divide the 
weight of the solid or liquid by the weight of the same 
volume of water. 

But the specific weight of a solid or liquid may be found 
in several other ways, directly or indirectly. The weight of 
1000 cubic centimeters of any liquid stated in kilograms at 
once expresses the specific weight of that liquid. Hence, if 
we have a flask with a long neck graduated by means of an 
etched line around the neck indicating the point to which 
one kilogram of water reaches at the standard temperature, 



254 A CORRESPONDENCE COURSE IN PHARMACY 

we may fill that flask up to the mark on the neck with any 
other liquid, take the weight of it, and thus at once find its 
specific weight. Graduated flasks of other capacities can, of 
course, be used for the same purpose. 

444. A pycnometer, or specific gravity bottle, is a flask con- 
structed to hold a given quantity of pure water at standard 
temperature when completely filled. The size of the flask is 
such that the weight of the water can be expressed in a 
simple number of weight units, such as will be an easy 
divisor, as, for instance, 50 or 100 or 500 or 1000 units. 
This bottle is then used in the same manner as the graduated 
flask already described. The most complete pycnometers 
made are glass-stoppered bottles provided with thermometers, 
so that the temperature of the liquid may be conveniently 
observed in the same operation with the determination of 
the weight of the contents. A counterpoise representing 
exactly the weight of the empty pycnometer accompanies 
the apparatus. The filled pycnometer is then placed on one 
pan of the balance and the counterpoise on the other, after 
which it is only necessary to restore the equilibrium of the 
balance by placing the requisite weights on the pan with the 
counterpoise. If the pycnometer is so made as. to hold 50 
grams of water, we can take the weight of the other liquid 
in grams, multiply that by 2 and divide the product by 100, 
when the quotient will be the specific weight sought. 

Any glass-stoppered bottle may be used for the same pur- 
pose, the weight of the water it will hold being taken and 
the weight of the other liquid required to fill the bottle also 
determined, after which the division follows. But when an 
ordinary bottle is used, the divisor, or the weight of the 
water the bottle holds, will not be a simple number of weight 
units, and the division will consequently not be so easy. 

Another way of finding the specific weight of a liquid is 
based upon the law of Archimedes. 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 255 

445. The law of Archimedes may be stated as follows: 
Any solid immersed in a fluid is buoyed up by that fluid 
with a force measured by the weight of the fluid displaced 
by the solid. If, for instance, a cubic inch of lead rests 
upon the table, it does not press upon its support with its 
whole mass, but with its mass minus the weight of a cubic 
inch of air, in which the piece of lead is immersed. The 
difference between the weight of that cubic inch of lead in 
a vacuum aud its weight in air must be, according to the law 
of Archimedes, the weight of one cubic inch of air. If the 
same cubic inch of lead be weighed suspended in water, the 
difference between its weight in air and its apparent weight 
when suspended in water will be the weight of one cubic 
inch of water. If it be weighed suspended in olive oil, then 
the difference between its weight in air and its weight in 
olive oil will be exactly measured by the weight of one cubic 
inch of olive oil. If a piece of glass or any other solid be 
weighed first in air and then in water while suspended from a 
balance by means of a wire or thread, the difference between 
its weight in air and its weight in water must be the weight 
of the same volume of water. If, now, the same piece of glass 
be weighed in any other liquid, the difference between the 
weight of the glass in air and its weight in the liquid must 
be the weight of the same volume of the other liquid. We 
then have the necessary factors from which to find the 
specific weight of the second liquid, namely, the weight of a 
definite volume of water and the weight of the same volume 
of the other liquid. We then divide the weight of the water 
into the weight of the other liquid. If the piece of glass 
used for this purpose be of such size that it displaces a simple 
number of weight units of water, as for instance 5 grams or 
10 grams, and the number of grams it displaces be known, 
it need not be weighed in waier again, but only in the liquid 
the specific weight of which is to be ascertained. 



250 A CORRESPONDENCE COURSE IN PHARMACY 

446. The specific weight of a solid heavier than water 
may be found by submerging the solid in water in a gradu- 
ated cylinder, as follows: If the cylinder is graduated in 
grams and fractions of grams and a solid whose weight in 
air is known in grams be dropped in the water contained in 
the graduated cylinder, then, as the solid sinks below the 
surface of the water, the level of the water necessarily rises 
to correspond with exactly the volume of the solid. If the 
solid weighs 10 grams in air, and when dropped in the water 
in the graduated cylinder causes the level of the water to 
rise 2 grams, according to the graduated scale, then the 
same volume of water weighs 2 grams, and the specific 
weight of the solid must be 5. 

447. Any solid having a specific weight greater than that 
of water must sink below the surface of the water when 
placed in it, and any solid having a less specific weight floats 
in water, and only descends into the water far enough to dis- 
place its own weight. 

Any solid having precisely the same density as that 
possessed by water may be placed in any position in the 
body of the water and will neither sink nor rise. 

Lard is lighter than water, but heavier than alcohol. The 
specific weight of lard may therefore be found by putting a 
piece of it in a vessel of water and then adding gradually 
enough alcohol, mixing the two liquids cautiously until the 
piece of lard may be placed in any part of the mixed liquid 
and will remain in its position without sinking or rising. 
The specific weight of the liquid is then taken and must, 
of course, be identical with the density or specific weight of 
the lard. 

448. Specific gravity beads are hollow glass beads the 
specific weights of which have been ascertained and etched 
upon them. If a handful of such beads be thrown into any 
liquid, the beads having a greater density than the liquid 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 257 

will sink to the bottom and those having a less density will 
float at the surface, but any bead having the same density as 
the liquid may be made to swim about in the body of the 
liquid in any position. The density of the liquid in this 
case is, of course, that marked upon the bead that neither 
sinks nor floats. This fact is taken advantage of for the 
purpose of finding deviations from the normal density of 
urine, for if a glass bead or bulb so made that it has precisely 
the specific weight of normal urine be put in a sample of 
urine, it will sink if the urine is abnormally light, or it will 
float if the urine is abnormally heavy. 

449. A hydrometer is a float of nearly cylindrical form 
loaded at one end with shot or mercury so as to bring the 
center of gravity of the whole instrument to that end, in 
order that when the hydrometer is placed in a liquid it may 
assume a vertical position. If the whole instrument weighs 
more than its own volume of the liquid in which it may be 
placed, it will, of course, sink below the surface of that 
liquid. If it weighs less than its own volume of that liquid, 
it will sink down into the liquid just far enough to displace 
its own weight of the liquid. The floating hydrometer, 
therefore, sinks farther down in a light liquid than in a 
heavy one, and the tube or stem of the hydrometer may be 
graduated, or provided with a graduated scale indicating the 
density of the liquid in which it may be placed. 

If the hydrometer is constructed especially to take the 
specific weights of heavy liquids, then the point to which it 
sinks in water is marked by the figure 1 at the top of the 
scale, and the point to which it sinks in a liquid having, for 
instance, a density twice as great as that of water would be 
marked 2, after which the distance between the two gradu- 
ation marks is accurately divided into equal spaces indicating 
the densities of liquids between ths specific weight 1 and 
the specific weight 2. 



258 A CORRESPONDENCE COURSE IN PHARMACY 

If the hydrometer is to be used to find the densities of 
liquids lighter than water, then the instrument is so made 
that it descends into the water only to the lower end of the 
scale. We shall then have the unit at the bottom of the 
scale and the densities of the lighter liquids graduated above 
as far as may be necessary. The most common hydrometers 
are of two kinds — one for densities ranging from 1.000 up 
to 1.300 and the other for densities ranging from 1.000 down 
to 0.700. 

Test Questions 

1. Define specific weight. 

2. What is the difference between specific weight and 
specific gravity ? 

3. Define specific volume. 

4. How are specific weights expressed ? 

5. What is the unit of expression for the specific weights 
of gases ? 

6. What is the unit of expression for the specific weights 
of liquids ? 

7. What unit is employed for expressing the specific 
weights of solids ? 

8. What is the quotient obtained when 1 is divided by 
the specific weight ? 

9. What is the quotient obtained when 1 is divided by 
the specific volume ? 

10. What is the specific volume of a liquid the specific 
weight of which is 1.111 ? 

11. What is the specific weight of a liquid the specific 
volume of which is 1.111 ? 

12. What is the product obtained from multiplying the 
specific volume of a substance by its specific weight ? 

13. What practical uses are made of specific weight ? 

14. What are the practical uses of specific volume? 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 259 

15. What is meant by commensurate units of weight and 
volume ? 

16. Name several pairs of such units. 

17. When it is stated that hydrochloric acid has the 
specific weight 1.160, what does that number mean ? 

18. What is the standard temperature adopted by the 
pharmacopoeia for finding and expressing specific weights ? 

19. Mention a convenient method of taking the specific 
weight of a fluid extract. 

20. Give a method of finding the specific weight of lead. 

21. What is a pycnometer ? 

-" 22. State the law of Archimedes. 

23. What are specific gravity beads ? 

24. Describe a hydrometer. 

25. A piece of metal weighs 8. 3 ounces. The same volume 
of water weighs 1 ounce. What is the specific weight of the 
metal ? 

26. A bottle holds 480 grains of water, but 576 grains of 
nitric acid. What is the specific weight of the acid ? 

27 If 20 imperial fluid ounces of a liquid weigh 1\ avoir- 
dupois pounds, what is the specific weight of the liquid ? 

28. A one-thousand-grain pycnometer holds 735 grains of 
ether. What is the specific weight of that ether ? 

29. A fluid ounce of alcohol at 22° 0. weighs 373 grains 
and a fluid ounce of water at the same temperature weighs 
455 grains. What is the specific weight of that alcohol 
referred to water at 22° 0. as unit ? 

30. Is the specific weight of that alcohol greater or less 
referring to water at 15° as unit ? 

31. A liter of diluted alcohol weighs 925 grams. What is 
its specific weight ? 

32. A liter of glycerin weighs 1250 grams. What is its 
specific weight ? 

33. A bottle which holds \ ounce of water holds 5 drams 



260 A CORRESPONDENCE COURSE IN" PHARMACY 

of a certain solution. What is the specific weight of that 
solution ? 

34. If 1 gallon of ether and \ gallon of chloroform have 
the same weight and 2 pints of chloroform weigh the same 
as 3 pints of water, what is the specific weight of the ether ? 

35. I have a solid weighing 13 grams in air. I drop it 
into a graduated cylinder containing 30 cubic centimeters of 
water and find that the level of the water rises to 40 cubic 
centimeters when the solid sinks to the bottom of the 
cylinder. What is the specific weight of the solid ? 

36. The weight of 3 gallons of water is 400 avoirdupois 
ounces and the weight of a gallon of alcohol is 109 avoir- 
dupois ounces. What is the specific weight of the alcohol ? 

37. An imperial gallon of oil of peppermint weighs 9 
avoirdupois pounds. What is its specific weight ? 

38. Six pints of solution of zinc chloride weigh 155^- 
avoirdupois ounces. What is its specific weight ? 

39. A mass of thirteen grams of a certain solid has a 
volume of 10 cubic centimeters. What is its specific weight ? 

40. A solid weighs 4.75 grams In air and 4 grams in water. 
What is its specific weight ? 

41. A piece of metal of the bulk of 161.7 cubic inches 
weighs 347624.55 grains in air and 306839.75 grains in water. 
What is the weight in grains of 231 cubic inches of water ? 

42. A crystal weighs 10 grams in air and 9 grams in oil of 
turpentine. The specific weight of the oil of turpentine is 
0.860. What is the specific weight of the crystal ? 

43. One cubic centimeter of a certain solid weighs 870 
milligrams. What is its specific weight ? 

44. A piece of cork weighs 0.732 grams in air. A piece 
of metal weighs 7.7 grams in air, but only 6.6 grams in water. 
Cork and metal tied together and weighed in water are 
found to weigh 4.182 grams. What is the specific weight of 
the cork ? 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 261 

45. A piece of lard is put in a vessel of water, and alcohol 
is gradually added and mixed with the water until the piece 
of lard instead of floating on the surface may be placed at 
will in any position in the body of the liquid. A fifty-gram 
pycnometer is now filled with the liquid and the contents of 
the pycnometer found to weigh 46.9 grams. What is the 
specific weight of the lard ? 

46. If a piece of metal weighs 9 ounces in air, 8 ounces in 
water and 8.1 ounces in oil, what is the specific weight of the 
oil? 

47. A solid measuring 10 cubic centimeters when immersed 
in oil of turpentine is found to displace 8.6 grams of the oil. 
What is the specific weight of the oil ? 

48. Glycerin has the specific volume 0. 800. The weight of 
three volumes of glycerin is the same as that of five volumes 
of ether. What is the specific weight of the ether ? 

49. Fifty cubic centimeters of nitric acid weigh 71 grams 
and 50 cubic centimeters of hydrochloric acid weigh 58 
grams. The specific weight of the hydrochloric acid is 
1.160. What is the specific weight of the nitric acid ? 

50. A certain bottle holds 100 ounces of glycerin, the 
specific weight of which is 1.250. How many ounces of 
water will it hold ? 

51. How much will the same bottle hold of ether having 
the specific weight 0.720 ? 

52. How much will it hold of chloroform of the specific 
weight 1.470? 

53. How much will it hold of syrup having the specific 
weight 1.330? 

54. A solid weighs 3 ounces. It has the specific weight 
of 8. 300. When weighed in a certain liquid its apparent loss of 
weight is \ ounce. What is the specific weight of the liquid ? 

55. The specific weight of water is 1. What is its specific 
volume? 



262 A CORRESPONDENCE COURSE IN PHARMACY 

56. One thousand avoirdupois ounces of a liquid measure 
60 pints. What is the specific volume ? 

57. If 300 grams of a liquid measure 280 cubic centi- 
meters, what is its specific volume ? 

58. One kilogram of a liquid measures 755 cubic centi- 
meters. What is the specific volume ? 

59. If 4 imperial pints of a liquid weigh 6 pounds, what 
is its specific volume ? 

60. What is the weight of 255 cubic centimeters of a 
liquid having the specific weight 1.100 ? 

61. What is the weight of 30 cubic centimeters of a 
liquid having the specific weight 0.700 ? 

62. What is the weight in avoirdupois ounces of 100 
imperial fluid ounces of a liquid having the specific weight 
1.960? 

63. What is the weight in pounds of an imperial gallon ? 

64. What is the weight in avoirdupois ounces of 96 
American fluid ounces of a liquid having the specific weight 
1.820? 

65. What is the weight in avoirdupois ounces of 16 United 
States fluid ounces of a liquid having the specific weight 
1.260? 

66. If a cubic inch of water weighs 252.5 grains, what is 
the weight of 231 cubic inches of a liquid having the specific 
weight 0.900? 

67. If an American fluid ounce of water weighs 0.95 
apothecaries' ounce, what is the weight of 1 American fluid 
ounce of a liquid having the specific weight 0.860 ? 

68. What is the volume of 3 kilograms of nitric acid 
having the specific weight 1.420 ? 

69. What is the volume of 5 pounds of a liquid having 
the specific volume 1.111 ? Give the answer in pints. 

70. Castor oil has the specific volume 1.042. What is the 
volume of 6 pounds stated in American fluid ounces ? 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 263 

71. A piece of metal weighs 6445.380 grains in air. When 
suspended in water, its apparent weight is 5585.996 grains. 
Its bulk is 3.40 cubic inches. What is the specific weight 
of the metal, and what is the weight of a cubic inch of 
water ? 

72. A piece of metal weighs 480 grains in air, 420 grains 
in water and 400 grains in a solution of sugar. What is the 
volume of 500 grams of that solution ? 

73. A kilogram weight of brass and a kilogram weight of 
platinum balance each other perfectly in a vacuum. Which 
has the greater mass ? 

74. Which has the greater volume ? 

75. Which of them seems to weigh more in air ? 

76. You weigh in the usual manner a pound of wood and 
a pound of lead. Which is really the heavier of the two ? 

77. A solid measuring 0.1 cubic decimeter is weighed first 
in vacuo, then in air, and lastly in water.' One cubic inch 
of air weighs 0.3 grains and a cubic inch of water 252.50 
grains. Find the difference between the weight of that solid 
in vacuo and its weight in air; the difference between its 
weight in air and its weight in water. 

78. A ten-dollar gold coin weighs 258 grains in air. 
Assuming its specific weight to be 18.300, what is its 
apparent loss of weight when weighed suspended in water ? 

79. If an imperial gallon of sulphuric acid weighs 18.35 
avoirdupois pounds, what is the volume of 1000 grams of 
that acid expressed in cubic centimeters ? 

80. If the specific weight of oil of vitriol be twice that of 
olive oil, and if 1. liter of olive oil weighs 917. grams, what 
is the weight of 500 cubic centimeters of oil of vitriol ? 

81. If a solid weighs 75 ounces and the same volume of 
water 10 ounces, what is the apparent weight of that solid 
when weighed suspended in water ? 

82. If a bullet weighs 13 ounces in air and 12 ounces in 



264 A CORRESPONDENCE COURSE IN PHARMACY 

water, what will it appear to weigh in a liquid having 1.400 
specific weight ? 

83. If a pound of water measure 15f fluid ounces and a 
pound of a certain solution 7^ fluid ounces, what is the 
specific volume of the solution ? 

84. What number of cubic centimeters expresses the 
volume of 85.33 grams of a liquid having 1.01 specific 
volume ? 

85. The specific weight of solution of mercury nitrate 
being 2.100, what is the weight of one liter of it ? 

86. Solution of citrate of iron has the specific weight 
1.260. What is the weight of one American pint in avoir- 
dupois ounces ? 

87. The specific weight of oil of turpentine is 0.860. 
What is the weight of 96 American fluid ounces of it in 
commercial ounces ? 

88. Which is greater, the number expressing the specific 
weight of acetic acid referring to water at 4° 0. as unit, or 
the number expressing the specific weight of the same acid 
referring to water at 15° C. as unit ? 

89. A certain liquid at 39.2° F. has the specific weight 
1.200 referring to water at 22° C. as unit. Will the number 
expressing its specific weight at 60° F. referring to water at 
4° C. as unit be greater or less than 1.200 ? 

90. The weight of one liter of water at 4° 0. is 15,432 
grains, but the weight of 500 cubic centimeters of water at 
22° C. is 7696 grains: 

(a) What is the specific weight of water at 22° C. referring 
to water at 4° C. as unit? 

(b) What is the specific weight of water at 4° C. referring 
to water at 22° C. as 1 ? 

91. An imperial gallon of water at 62° F., barometer at 30 
inches, weighs 70,000 grains: 

(a) Does it weigh more or less at 15° C. ? 



SPECIFIC WEIGHT AND SPECIFIC VOLUME 265 

(b) Does it weigh more or less when the atmospheric pres- 
sure is greater ? 

92. A cubic inch of water at 22° 0. weighs 252.5 grains. 
What is the weight of 231 cubic inches of an alcohol having 
0.860 specific weight, referring to water at 22° C. as 1 ? 

93. What is the volume of 100 apothecaries' ounces of oil 
of 0.900 specific weight, if one cubic inch of water weighs 
250.5 grains? 

94. What is the specific volume corresponding to each of 
the following specific weights, respectively: (a) 1.000; (#) 
1.250; (c) 1.333; (d) 0.500; (e) 0.750; (/) 0.800; (g) 
2.000; (70 0.720; (i) 0.820; (/) 0.950; \k) 1.500; (J) 
1.300; (m) 1.320? 

95. What is the volume of 1000 grams of a liquid having 
the specific volume 1.200 ? 

96. What is the volume in imperial fluid ounces of 100 
avoirdupois ounces of a liquid having the specific volume 
0.800? 

97. What is the volume in United States fluid ounces of 
25 avoirdupois ounces of a liquid having the specific volume 
1.000 ? 

98. What number of cubic centimeters expresses the 
volume of 85 grams of a liquid having the specific weight 
1.010 ? 

99. What number of cubic centimeters expresses the 
volume of 85 grams of a liquid having the specific volume 
1.010? 

100. What number of grams expresses the weight of 85 
cubic centimeters of a liquid having the specific weight 
1.010 ? 

101. What number of grams expresses the weight of 85 
cubic centimeters of a liquid having the specific volume 
1.010? 

102. The total weight of a bottle filled with water is 30 



266 A CORRESPONDENCE COURSE IN PHARMACY 

ounces. The same bottle filled with olive oil weighs 28 
ounces. What is the weight in ounces of the water the 
bottle is capable of holding ? How many ounces of oil will 
it hold ? What is the weight of the bottle itself ? 

103. A bottle filled with water weighs 16 ounces ; filled with 
chloroform having the specific weight 1.470 it weighs 19.877 
ounces; filled with acid it weighs 17.32 ounces. How much 
does it hold of water, of chloroform and of acid, respectively, 
and what is the specific weight of the acid ? 

104. A solid measuring 2 cubic inches weighs 6000 grains 
in air, but only 5400 grains when weighed suspended in a 
certain liquid. What is the specific weight of that liquid ? 

105. A solid measuring one cubic centimeter and weighing 
10 grams loses one gram in weight when weighed in a certain 
liquid. What is the specific weight of that liquid? 

106. Alcohol has the specific weight 0.820 at 15.6° C. 
The net weight of a barrel of alcohol at that temperature is 
found to be 300| pounds. How many gallons of the alcohol 
does that barrel contain ? 

107. A certain mixture of water with a syrup of the 
specific weight 1.330 is found to have the specific weight 
1.200. What are the proportions of syrup and water in the 
mixture ? 



LESSON EIG-HTEEN 



XXVII 



in 



Pharmaceutical Operations 

450. Heat for pharmaceutical purposes may be obtained 
most conveniently by means of gas burners, but where gas is 
not available, coal oil and alcohol lamps or burners are used. 

The Bunsen burner is the most approved gas burner for 
pharmaceutical and chemical purposes. It is a tube 
which the gas is mixed with air 
admitted near the bottom of the \ 

tube, and the mixture ignited at / i 

the top. The flame of the gas / A \ ! { 

burner is bluish when sufficient 
air is mixed with the gas so that 
the combustion is complete, but 
when the gas supply is too abun- 
dant or the amount of air insuffi- 
cient, the flame is yellow and 
deposits unconsumed carbon upon 
the vessels heated over the flame. 

451. The sand bath is an iron dish containing a layer of 
sand which may be used for the purpose of distributing the 
heat of the flame. The flask, dish or other vessel to be 
heated is placed in the sand. 

A water bath is a vessel of water intervening between the 
flame and the vessel to be heated. The object of the water 
bath is to prevent the temperature from rising above the 
boiling point of water. The contents of vessels heated upon 

267 



BUNSEN BURNER, CONTRASTING 
THE PROPER FLAME WITH ONE 
THAT RESULTS WHEN THE GAS IS 
"LIGHTED BACK" INTO THE TUBE 



2G8 A CORRESPONDENCE COURSE IN PHARMACY 

the water bath rarely attain a higher temperature than a 
little above 90° 0. To control the temperature when 
substances must be heated above 100° 0., glycerin baths, 
oil baths and solution baths are employed. 

452. Exsiccation is a term used to express the heating of 
chemical compounds for the purpose of expelling water of 
crystallization. Sulphate of iron, alum, sodium carbonate, 
sodium phosphate, magnesium sulphate and various other 
salts containing large quantities of water of crystallization 
may be dried so as to expel all water or a portion of it. 

453. Calcination is the process of converting metallic 
carbonates and other metallic salts into metallic oxides by 
heat. Strong heat is usually required for this purpose, and 
the by-products formed are volatile. When a carbonate is 
calcined, the by-products are 00 2 and water, or C0 2 alone, 
according to the composition of the carbonate decomposed. 
Nitrates and sulphates can also be calcined. The word 
calcination is derived from the Latin calx, which means lime, 
because lime is produced by strongly heating limestone or 
calcium carbonate in kilns. 

454. Dry distillation, or "destructive distillation," is a 
term employed to express the decomposition of organic 
substances by strong heat, resulting in the formation of new 
products, some of which are volatile and others fixed. For 
example, when oak billets are heated strongly in closed iron 
cylinders provided with an outlet for the volatile products, 
the oak wood undergoes decomposition, and, among the 
volatile products which distill over, acetic acid is one of the 
most valuable, and the residue in the cylinder is a tarry 
mass of mixed composition. 

455. Sublimation is the distillation of solids; in other 
words, volatile solids are vaporized, and the vapor conducted 
into condensing vessels in which they reassume a solid form. 
The product is called a sublimate, and is generally of 



PHAEMACEUTICAL OPERATIONS 269 

crystalline character. Sublimation is employed as a method 
of separation of volatile substances from fixed substances for 
purposes of purification. 

456. The coarse mechanical division of drugs is an im- 
portant pharmaceutical operation. 

For the preparation of mixed teas, drugs are required to 
be very coarsely comminuted. If they are flexible, they may 
be cut with sharp-edged tools so as to produce pieces free 
from dust or powder, but if they are hard so that they 
cannot be cut, they are comminuted by crushing, in which 
case more or less powder is unavoidably produced. The 
crushing of plant drugs is best accomplished in an iron 
mortar with an iron pestle, but smaller pieces of drugs can 
be crushed also in hand-mills of iron. 

457. An iron mortar used for crushing and powdering 
drugs must be very large in proportion to the amount of 
drug operated upon in order to do effective work. It should 
be solid, heavy, and placed upon a solid block, which, if 
possible, should rest upon the ground instead of upon the 
floor. The crushing of drugs in a mortar by means of blows 
with the pestle is technically called contusion. 

458. The iron mill used by druggists for making coarse 
powders of drugs is similar to the mill used by grocers for 
grinding coffee, but there is an essential difference in the 
construction and position of the grinding plates, so that 
the hand drug-mills are not identical with coffee mills and 
spice mills. There are several makes of hand drug-mills, 
and the best forms are those which have the grinding plates 
in a nearly horizontal instead of vertical position. 

These hand-mills are provided with set-screws which 
enable the operator to move the grinding plates nearer to 
each other or farther apart at will, to make coarser or finer 
powder, as may be desired. It is usually necessary to pass 
a drug through the hand-mill more than once, if a com- 




A SMALL PORCE- 
LAIN MORTAR 



270 A CORRESPONDENCE COURSE IN PHARMACY 

paratively fine powder is required ; in other words, the drug 
is first crushed, then passed through the mill to make a 
coarse powder, then the mill is set finer and the coarse 
powder passed through the mill again, this operation being 
repeated until the required fineness is attained. But very 
fine powder cannot be made with the hand drug-mill. 

A coarse powder can, however, be easily enough made 
very fine by contusion in the iron mortar. 

459. Trituration is the grinding produced in the mortar 
by a rotary motion of the pestle accompanied by pressure. 

When trituration is performed, the pestle 
is grasped firmly by the whole hand in order 
to apply sufficient force to crush the parti- 
cles of substance triturated. Comparatively 
brittle substances can be powdered by tritu- 
ration, but in order to do effective work 
the trituration mortar should be large in 
proportion to the quantity of substance triturated, for if 
too deep a layer of powder is operated upon at one time, 
the operation is necessarily slower. 

Trituration is also employed for mixing powders, but if 
the ingredients of the mixture are already sufficiently fine, 
no pressure is required 'n mixing them. The spatula is 
usually necessary, in ac- 
complishing trituration, 
to scrape the substances 
from the end of the pes- A steel spatula 

tie and the bottom and 

sides of the mortar, in order to do rapid and effective work. 
Trituration mortars are generally made of porcelain or of 
Wedgewood ware. 

460. Levigation is the trituration of substances in a fine 
state of division, either upon a slab with the muller or in a 
mortar with the pestle, with the addition of some liquid to 



PHARMACEUTICAL OPERATIONS 271 

the solid substance to aid in its further division. Water, 
alcohol and oil are all used for such purposes. 

Sometimes the levigation has for its object not only the 
production of a very fine powder, but also the removal of 
impurities with the aid of the liquid added. For example, 
calomel is levigated by trituration with water in order to 
wash out from it the corrosive sublimate which may be con- 
tained in sublimed calomel and which is soluble in water. 
When purification of calomel is effected by levigation, several 
successive portions of water must, of course, be used until 
all of the corrosive sublimate has been finally removed. 

461. Elutriation is also a process employed for the purpose 
of producing very fine powders of insoluble substances. 
The finely powdered solid is put in water, with which it is 
well mixed by stirring. The mixture is then allowed to 
stand at rest until the coarser and heavier particles have 
subsided, while the finer particles still remain suspended in 
the liquid, which is decanted, after which the finer powder 
is allowed to settle to the bottom. When this process is 
repeated several times an almost impalpable powder can be 
produced. Prepared chalk and purified antimony sulphide 
are prepared by elutriation, according to the directions of the 
pharmacopoeia. 

462. Powders, however they may be made, are never 
perfectly uniform. To render them as nearly uniform as 
practicable they are passed through sieves made out of 
sieve-cloth of various grades of fineness. The fineness of 
sieves is indicated in the pharmacopoeias according to the 
number of meshes in the sieve-cloth. Sometimes the number 
of meshes is counted according to linear measure, but a 
better way is to count the number of meshes per square 
measure. In the United States pharmacopoeia the fineness 
of sieves and powders is indicated by the number of meshes 
to the linear inch. Thus, a No. 60 sieve means a sieve 



Z72 A CORRESPONDENCE COURSE IN PHARMACY 

having sixty meshes to the linear inch, and a No. 80 sieve 
*s one having eighty meshes to the linear inch. But the 
meshes of sieve-cloth are not always square, so that a 
different number of meshes may be counted to the linear 
inch, according to whether the count is made along the 
woof or along the warp. Moreover, the wire or silk thread 
or hair out of which the sieve-cloth is made may be of 
varying caliber, so that this method of determining the 
fineness of powders is very uncertain. The student will 
readily understand this by an extreme example: Suppose 
a sieve has one hundred meshes to the linear inch and is 
made of brass wire. If the wire cloth is made of wire one 
one-hundredth part of an inch in diameter, it follows that 
there would be no openings in the sieve-cloth at all. 

463. While the pharmacopoeias always prescribe a method 
of expressing the fineness of powders, they do not all of 
them prescribe a given degree of fineness for each individual 
drug. In the American pharmacopoeia, for instance, there 
is no information given as to how fine powdered digitalis 
should be when ordered by the physician, although the 
powder to be used of digitalis for the preparation of the 
tincture, the fluid extract or the extract is specifically 
prescribed. Very full directions are given in some pharma- 
copoeias, stating how fine the powder should be of any 
important drug prescribed by a physician to be used in 
powder form or in pill-masses, and to fail to give such 
directions would seem to be a serious omission. 

464. By "dusted powders" is meant powders so fine that 
when made in a mill constructed expressly for the purpose, 
they rise in the mill-box like dust, which settles upon shelves 
along the walls of the mill-box or on the floor of that box 
away from the circle in which the millstones run like 
wheels. 

465. Colored substances become lighter when reduced to 



PHARMACEUTICAL OPERATIONS 



273 



fine powder, and the color grows lighter as the powder gets 
finer. 

466. The solution of soluble substances may be effected 
in many different ways, but most quickly by reducing the 
substance to be dissolved to a more 
or less fine powder, except in cases 
where the fine powder would be- 
come agglutinated by the action 
of the solvent. A solution mortar 
is a deep mortar provided with a 
lip. A salt or other substance to 
be dissolved in water may be put 
in the solution mortar and there 
crushed, after which one portion 

after another of solvent is added and poured off as solution 
results, until all of the solvent to be used has been employed 
and the solid substance liquefied. 




A PORCELAIN SOLUTION 
MORTAR 





A BEAKER WITH LIPS, USED IN 
MAKING SOLUTIONS 



A BEAKER WITHOUT LIPS, USED 
IN MAKING SOLUTIONS 



467. Circulatory displacement consists in placing a soluble 
substance on a strainer at the top of a vessel containing the 
solvent, just below the surface of the liquid; the solution 



274 A CORRESPONDENCE COURSE IN PHARMACY 

formed, being denser than the solvent itself, then runs down 
to the bottom of the vessel so that fresh portions of solvent 
come in contact with the solid matter, and the solution is 
thus more rapidly effected. This method is a very useful 
one, and if a strainer of the right kind is employed the 
solution obtained by circulatory displacement may be 
rendered so clear as not to require further clarification. 

468. Extraction methods by which soluble substances 
contained in plant drugs are extracted and separated from 
the insoluble substances are of great importance. The 
solvents employed are called " menstrua,' ' and the most 
common menstrua are alcohol and water and mixtures of 
these. The extraction methods are maceration, digestion, 
infusion, decoction and percolation. 

469. Maceration consists in placing the comminuted drugs 
in the menstruum and permitting them to remain in contact 
with each other a sufficient length of time at the ordinary 
room temperature, after which the solution obtained is 
separated from the undissolved residue, which is called the 
"marc." 

But maceration may be varied so as to be rendered more 
effective, by using several successive portions of menstruum 
upon the undivided amount of drug to be exhausted of its 
soluble matter. If, for instance, a pound of drug be mixed 
with enough diluted alcohol to produce a thick mixture, and 
this mixture be allowed to stand a day or two, after which 
the solution formed is expressed by means of a hydraulic 
press or other effective pharmaceutical press, the press-cake 
can then be disintegrated again and mixed with another 
portion of fresh menstruum to produce a thick mixture as 
before, allowing this new portion of menstruum to extract 
as much of the remaining soluble matter as it may, after 
which this second solution is separated by expression as 
before. These successive macerations with new portions of 



PHARMACEUTICAL OPERATIONS 275 

menstruum may be repeated until absolutely no more soluble 
matter remains in the drug. 

If at the same time the several macerates or solutions 
obtained by maceration be kept separate from one another, 
these several macerates may be employed over again as 
menstrua upon a fresh portion of drug, the drug being 
macerated first with the first macerate from the preceding 
portion of drug and then with a second and third and fourth 
macerate, and finally with a fresh portion of previously 
unused menstruum, until this second portion of drug has 
also been completely exhausted, the object being to use each 
portion of menstruum over and over again as long as it still 
retains any solvent power, in order to effect the extraction 
of all the soluble matter with the smallest possible amount 
of menstruum, so as to obtain as concentrated a solution as 
may be made. [This is also the object of percolation and 
re-percolation, as will be seen later on.] A very common 
form of maceration when employed in the preparation of 
tinctures is to use two-thirds of the whole amount of 
menstruum upon the whole amount of drug in the first 
period of maceration, and then, after separating the solution 
formed, to use the remaining third of the menstruum to 
finish the exhaustion of the drug. 

470. Digestion differs from maceration in one particular 
only, namely, the temperature. While maceration is per- 
formed at any ordinary room temperature, or, in other 
words, without the application of artificial heat, digestion 
is performed at any temperature above that of the work- 
room, or, in other words, with the application of more or 
less heat. 

The temperature of digestion may be any degree of heat 
from 25° 0. up to nearly 90° 0. 

The effectiveness of digestion as compared with maceration 
is great, and the employment of even a comparatively 



276 A CORRESPONDENCE COURSE IK PHARMACY 

moderate degree of heat generally increases the solvent 
power of the menstruum so greatly that digestion ought to 
be employed more largely than it is, for it accomplishes in 
great part the same object as is gained by percolation and 
re-percolation, namely, the exhaustion of the drug with a 
minimum amount of menstruum. 

471. Infusion is a process consisting of putting boiling 
water upon a plant drug and letting the hot water exert its 
solvent action upon the drug without taking any measures 
to maintain the temperature, but allowing that to gradually 
fall even to the temperature of the atmosphere of the room, 
after which the solution formed is separated from the marc 
by straining and expression. But the process of infusion is 
at the present time most frequently performed by means of 
a water bath or "digestorium," and when this is the case, 
the temperature is maintained at such a high degree that 
che result is very different from that obtained by the old 
method of infusion. The products or preparations made by 
the process of infusion are generally called infusions. 

472. Decoction is a process of extraction consisting of 
boiling a drug in the menstruum for a given length of time. 
This process is rarely applicable except when water is the 
menstruum and the drug contains no substance of value 
liable to be injuriously affected by the high temperature. 
The products made by decoction are called "decoctions," 
and decoctions are rarely made of potent drugs. 

473. Percolation is an effective method of extraction which 
is extremely useful when concentrated liquid extracts are to 
be made or when it is desired to exhaust the drug with a 
minimum amount of menstruum. These objects are gained 
in the process of percolation by using the same quantity of 
solvent over and over again on successive portions of drug, 
until the solvent is so charged with soluble matter or so 
nearly saturated that it is no longer capable of doing 



PHARMACEUTICAL OPERATIONS 



277 



effective work. This can be accomplished in various 
ways. 

The simplest form of percolation consists in moistening 
the drug in the form of powder with a sufficient amount of 
menstruum to dampen it, after which the dampened powder 
is allowed to lie long enough thoroughly 
to absorb the menstruum, so that 
each particle of powder may be soft- 
ened and permeated by the solvent as 
far as it can be. The dampened drag 
is then packed more or less firmly in 
a tall cylindrical tube called a perco- 
lator, the form of which is indicated 
by the illustration on this page. If 
the drug is uniformly and not too 
firmly packed in the percolator by 
means of the plunger or packer, the 
descent of the menstruum, afterwards 
poured upon the drug, will be very 
regular. A sufficient quantity of men- 
struum is poured upon the drug in 
the percolator completely to saturate 
the packed drug from top to bottom, 
leaving a layer of menstruum above 
the surface of the drug, after the 
packed mass has been filled and satu- 
rated. The apparatus is closed so that no liquid can pass 
out from it. In the percolator described in the pharma- 
copoeia and figured in the text, a rubber tube is attached 
to the lower end of the percolator, and when this tube 
is raised and tied to the side of the percolator so that 
the end of the tube is above the level of the liquid, the 
atmospheric pressure will prevent any portion of liquid from 
passing out. The apparatus is left in this condition a greater 




OLDBERG'S PERCOLATOR 



278 A CORRESPONDENCE COURSE IN PHARMACY 

or less period of time, according to circumstances, in order 
that the menstruum may have time enough to act upon the 
drug and to dissolve the soluble substances in it. The tube 
is then lowered and the displacement of the liquid from the 
mass of drug in the percolator is allowed to proceed. The 
liquid or solution flowing out of the percolator is called the 
percolate, and the rate of its flow is regulated so that it may 
pass out slowly, the object being to permit the liquid in the 
percolator to gather up more soluble matter as it passes 
through successive layers of the packed drug. 

The student can readily see that when the menstruum is 
poured upon the drug in the percolator, each drop of liquid 
passes through the entire distance from the top to the 
bottom, first taking up soluble matter from the upper layer 
and then from the next layer of drug, and so on, so that 
if the column of drug is tall enough, it may happen that 
the solution formed will finally be so thick that it can pass 
no further. This, of course, is to be avoided, but the 
column of drug is always made sufficiently tall to insure that 
the menstruum may form as saturated a solution as can 
readily pass down and out. 

If the process is successfully performed, the percolate 
passing out from the percolator will be clear or free from 
solid particles. 

Fresh menstruum is added from time to time, being 
poured into the percolator at the top and allowed to percolate 
through the drug, following the preceding portions until 
finally no more soluble matter remains in the marc. 

If the percolator is put in a warm place, the effectiveness 
of this operation is very much increased. 

When liquid preparations are made of such strength that 
they represent more than one-fifth of their weight of the 
drug, percolation is unquestionably the best method of 
extraction, but most of the pharmacopoeias of the world 



PHAKMACEUTICAL OPEEATIOKS 279 

order maceration for making tinctures of 20 per cent, 
strength or less. 

Percolation is a difficult process, which should never be 
undertaken by inexperienced operators without constant 
supervision exercised by persons familiar with the necessary 
conditions- of success. In other words, it requires con- 
siderable practice and close attention to perform percolation 
successfully. Maceration, on the other hand, is a very 
simple process, and this undoubtedly is the reason why most 
of the pharmacopoeias prefer it to percolation, except in 
cases where maceration proves insufficient. 

474. By re-percolation is meant a process of percolation 
in which one portion after another of the drug is subjected 
to displacement or percolation in the manner described, 
using part of the same menstruum for the second portion of 
drug as for the first, and part of the same menstruum for 
the third portion of drug as for the second. This plan is 
adopted for the purpose of further increasing the effective- 
ness of the process. In simple percolation the last portion 
of the percolate is a comparatively diluted solution, which 
can readily be used again as an effective menstruum, and it 
is so used when re-percolation is employed. (See p. 275.) 

475. The clarification of liquids is accomplished in various 
ways. Sometimes clarification is effected by subsidence, 
the solid particles suspended in the liquid being simply 
permitted to sink to the bottom, forming a sediment from 
which the clear "supernatant liquid" may be decanted by 
means of a siphon. 

The decantation of liquids from sediments and precipitates 
and the transfer of liquids from one wide-open vessel to 
another may also be effected in the manner shown in illus- 
trations on page 280. 

Another method of clarifying a liquid is by passing it 
through a straining cloth or bag. This is called eolation. 



280 



A CORRESPONDENCE COURSE IN PHARMACY 



and the strained liquid obtained by eolation is called the 
colature. 

476. Another and still more effective method of clarification 
wherever practicable is to pass the liquid through a paper 





DECANTATION BY A GUIDING ROD 



DECANTATION OVER A GREASED RIM 



filter. Paper is manufactured expressly for this purpose and 
called filter paper. It is usually obtained in circular disks 
of various diameters, and these disks, when folded, form the 
paper filters which are placed in glass funnels in order to 
perform the filtration. 

A simple paper filter is one so folded that when bent in 
the funnel it lies close against the sides of the funnel all 
around, leaving no channels through which 
the liquid can pass out. Such filters are 
useful in washing precipitates, but as the 
liquid can pass out of the paper filter only 
at the apex in the throat of the funnel, the 
process of filtration with simple filters is 
very slow. Plaited filters are so folded as 
to leave channels between the filter paper 
and the funnel all around, and such filters, 
of course, permit of rapid filtration. The pores of the filter 
paper are close enough or small enough to arrest the passage 
of all solid particles, so that the filtrate is usually perfectly 
clear. However, some substances in a very fine state of 




A PLAITED PAPER 
FILTER 



PHARMACEUTICAL OPERATIONS 



281 




A PLAIN PAPER 
FILTER IN POSITION 



division pass through the pores of filter paper so readily that 

they cannot be separated by this method. In such cases 

double or triple filters may sometimes prove 

effective, or the unclear liquid first may be 

mixed with magnesium carbonate or calcium 

phosphate, or some other insoluble filtering 

medium in the form of powder, through 

which the liquid must pass before it can 

run out of the filter. The use of a layer 

of wetted magnesium carbonate, calcium 

phosphate or other filtering medium put in 

the paper filter often proves sufficient to 

clarify liquids which cannot be rendered 

clear by paper alone. 

477. The process of evaporation as carried out for pharma- 
ceutical purposes is comparatively simple. "Evaporating 
dishes," or vessels in which liquids are heated to evaporate 
them, are shallow, in order that the liquid contained in 
them may present a large surface exposed to the air. The 
rate of evaporation is further facilitated or increased by 
stirring, which causes the vapor formed in the body of the 
liquid to be more readily disentangled so that it can escape. 
Eapid evaporation is called vaporization. The term 
"spontaneous evaporation" means the slow evaporation of 
liquids which takes place at ordinary 
temperatures, or, in other words, without 
the application of artificial heat. 

478. Distillation is the vaporization of 

liquids in an apparatus so constructed 

that the vapor is again condensed to a 

liquid form and the distilled liquid, called the distillate, 

collected. 

479. Pharmaceutical stills are usually made of copper or 
tinned iron, and they are also usually provided with water 




A PORCELAIN EVAPO- 
RATING DISH 



282 A CORRESPONDENCE COURSE IN PHARMACY 

baths or doable bottoms' so that they can be used with 
water-bath heat. 

Water stills for making distilled water are not provided 
with water baths, because the heat applied to them must be 
sufficient to produce rapid distillation of the water. But 
when alcohol and other more volatile liquids are to be dis- 
tilled, water-bath heat is not only sufficient but also much 
safer, if the liquid contains in solution substances liable to 
be injured by high temperatures. 

Stills of the most simple construction are the best, because 
they can be most readily cleaned and kept in order. Manu- 
facturers of pharmaceutical apparatus have various kinds to 
offer, and students as well as pharmacists are freely supplied 
with illustrated descriptive catalogues of such apparatus, 
from which they may learn about the various forms of 
construction. 

480. Condensers used in connection with stills are also of 
various kinds. 

The usual condensing worm, or worm-condenser, consists 
of a spirally bent block-tin tube or glass tube, placed in a 
vessel of water so that it may be surrounded by cold water, 
called the condensing water, which is intended to absorb the 
latent heat given up by the vapor as it reverts to the liquid 
form. 

Liebig^s condenser consists of two tubes, one without the, 
other. The inner tube is the one through which the vapor 
is conveyed, while the outer tube holds the condensing water. 
The outer tube is, of course, open at both ends, so that the 
condensing water may pass through it. The condenser is 
placed in a slanting position and the condensing water is 
admitted at the lower end and runs out at the upper end. 

Mitscherlich's condenser consists of three tubes. The 
outer tube is a large tank containing the condensing water. 
In this is placed a double cylinder, composed of two tubes 



PHARMACEUTICAL OPERATIONS 283 

soldered together at the ends. An opening into the space 
between the two tubes is made both at the top and at the 
bottom. The space between the tubes is the condensing 
space, and the condensed liquid runs out at the bottom of 
the apparatus, through a tube leading from the lower open- 
ing of the double cylinder through the wall of the tank. 
The student will see that the vapor to be condensed, being 
contained in the space between the two tubes constituting 
the double cylinder immersed in the tank, must form a thin 
sheet surrounded by water on both sides, for the condensing 
water passes all around the outer one of the two tubes 
forming the double cylinder and fills the inner tube com- 
pletely. This is the most effective condenser that can 
possibly be constructed. 

The dome-shaped condenser has a funnel-shaped still-head, 
or top of the still. This funnel-shaped top constitutes the 
bottom of a water vessel. In other words, the inverted 
funnel is surrounded along the lower edge by a wall so that 
the water can be kept on top of the funnel. The liquid 
heated in the still below forms vapor, which rises to the 
dome-shaped top and condenses against the sides of the 
dome or inverted funnel, and then runs down the sides to a 
gutter running along the inner and lower edge of the 
funnel. This gutter is lower at one point than elsewhere, 
so that the liquid runs out at that point through a tube. 
This dome-shaped condenser, in combination with the body 
that belongs to it, is one of the most useful pharmaceutical 
stills. 

Condensers made of glass are also in various forms, and 
are used in connection with flasks and retorts employed in 
distilling comparatively small quantities of liquids. 

481. Crystallization is the formation of regular geometric 
solids resulting from the arrangement of the molecules in 
accordance with inherent natural laws. Solid substances 



284: A CORRESPONDENCE COURSE IN PHARMACY 

assume the crystalline form most readily when passing from 
a liquid form in the state of solution, or from a state of 
vapor, back to the solid condition; but crystallized and 
crystalline substances are also obtained by precipitation and 
in other ways. 

The most common method of making crystals is to dissolve 
the crystallizable substance in a suitable solvent, after which 
the solvent is separated from the solution by evaporation. 
As soon as the solution becomes supersaturated, the dissolved 
substance separates in the form of crystals. 

A saturated solution may also be made at a high temper- 
ature, and then cooled to a lower temperature, at which the 
amount of solvent present is no longer sufficient to hold the 
substance in solution. Large and well-defined crystals are 
most readily obtained by slow concentration of solutions, for 
crystals grow by deposition of more of the solid matter on 
the surface of the smaller crystals, or nuclei, first formed. 

Special vessels for making crystals from solutions are 
called crystallizers. As the crystals are formed from 
solutions, on account of the deficiency of solvent, it follows 
that the liquid remaining after the crystallization must 
always be a saturated solution. This saturated solution in 
which crystals are being formed is called the "mother- 
liquor." When crystals are formed very rapidly and when 
the liquid in which the crystals are being formed is agitated 
in any way, the crystals are necessarily small and not well- 
developed. The formation of small crystals obtained by 
rapid evaporation accompanied by stirring or by rapidly 
cooling a hot saturated solution is called granulation. 

Pharmacists are sometimes required by physicians' pre- 
scriptions to make saturated solutions of medicinal sub- 
stances. When such solutions are dispensed, it happens 
that if the liquid is placed in a cold room, some of the dis- 
solved matter separates in crystalline form; to prevent 



PHAEMACEUTICAL OPERATION'S 285 

this, directions should be given to keep this preparation in 
a warm place. 

Crystals obtained by sublimation are usually quite small, 
especially if the vaporized substance is condensed at a 
temperature considerably below that at which the vapor was 
formed. 

A cake, or large crystals, may be obtained when the vapor 
is slowly condensed at a temperature but little below the 
heat required for the sublimation. 

Crystals can also be obtained by fusing crystallizable solids 
and permitting the fused substance to cool gradually. 

482. Precipitation is the formation of insoluble solids in 
liquids. It takes place in a liquid previously free from 
undissolved matters, and consists in the formation of solid 
particles insoluble in that liquid. It # is caused by a change 
in the relation of the solvent to the matter held in 
solution. It may, therefore, result from a change in the 
solvent or by a change in the substances dissolved in the 
liquid. 

Physical precipitation results when a non-solvent is added 
to the solution, as, for instance, when water is added to an 
alcoholic solution of a resin. The resin precipitates because 
it is insoluble in a mixture of alcohol and water. Alcohol 
precipitates mucilage from a water-solution for a similar 
reason, mucilage being insoluble in alcohol. Many metallic 
salts which are soluble in water are insoluble in alcohol, and 
for this reason strong water-solutions of such salts cannot 
be mixed with alcohol without causing the separation of the 
salts. 

Chemical precipitation results from the formation of new 
substances insoluble in the liquid. It is, in other words, 
the result of chemical reaction. When physical precipitation 
takes place, the molecules at the end of the process are the 
same as at the beginning, but in chemical precipitation the 



286 



A CORRESPONDENCE COURSE IN PHARMACY 




molecules present at the beginning give place to entirely new 
molecules. In most cases the reaction which takes place is 
one of double decomposition. 

When precipitates are intentionally made, the product 
sought may be either the insoluble substance itself or the 
soluble substance remaining in solution in 
the liquid. 

The "supernatant liquid" standing over 
the precipitate is called the mother -liquor. 

When the principal product consists of 
the precipitate, the latter must be washed 
with pure water until free from mother- 
liquor, when it is collected and dried. 
Heavy precipitates which readily subside in 
the liquid are easily washed, but light and 
P^bulky precipitates which remain suspended 
3njar in the liquid longer are sometimes difficult 
to handle. In cases of double decomposi- 
tion, coarser and heavier precipitates may often be obtained 
by using strong, hot solutions of the factors of the reaction, 
while more finely divided and bulky precipitates are formed 
when the solutions used are cold and 
diluted. 

Precipitates unintentionally formed 
in certain pharmaceutical preparations 
are often troublesome, and they always 
indicate that a change has taken place 
which may lessen the value of the 
preparation. 

The process of precipitation em- precipitation flasks, 

J- ^"""» ^ if ^ F CALLED ERLENMEIER FLASKS 

ployed for the production of chem- 
ical compounds is, of course, intentional, and can gen- 
erally be regulated so as to give entirely satisfactory 
results. 




PHARMACEUTICAL OPERATIONS 287 

Test Questions 

1. Describe a Bunsen burner. 

2. What is the object of the sand bath ? 

3. For what purposes is the water bath used ? 

4. What other means are employed to prevent the 
temperature from rising too high in pharmaceutical oper- 
ations requiring high heat ? 

5. What is exsiccated alum ? 

6. What is calcined magnesia? 

7. By what means can volatile substances be separated 
from fixed substances in a solid condition ? 

8. By what means is the coarse comminution of plant 
drugs effected ? 

9. By what means can the druggist make fine powder of 
roots and barks ? 

10. What is the difference between contusion and 
trituration ? 

11. What is levigated calomel and what is the difference 
between it and sublimed calomel ? 

12. How is prepared chalk obtained in such extremely fine 
powder ? 

13. What is a No. 50 powder ? 

14. Are all powders that pass through a No. 80 sieve of 
the same degree of fineness ? 

15. What is meant by dusted powders ? 

16. Why is powdered guaiac resin almost white, although 
the resin in the whole piece appears almost black ? 

17. For what reasons can soluble salts be dissolved more 
quickly with the aid of the solution mortar ? 

18. Describe circulatory displacement. ■ 

19. What are the most common pharmaceutical menstrua ? 

20. What is the difference between maceration and 
digestion ? 



'288 A CORRESPONDENCE COURSE IN PHARMACY 

21. What is the most effective method of maceration ? 

22. What is meant by the term marc ? 

23. Which is the more effective method of extraction, 
maceration or digestion ? State the cause of the difference, 
if any. 

24. What is meant by the process of infusion ? Describe it. 

25. Describe decoction. 

26. For what purposes is percolation employed ? 

27. Describe succinctly the various steps of the process of 
percolation. 

28. Describe a percolator. 

29. Why is the drug moistened before being packed in a 
percolator for percolation ? 

30. How tall can the column of packed drug be in the 
percolator without disadvantage ? 

31. What is meant by re-percolation ? 

32. Why is percolation more effective than maceration ? 

33. What results can be accomplished by percolation which 
cannot be accomplished by ordinary maceration ? 

34. Can all drugs be subjected to percolation ? If not, 
what drugs cannot be so treated ? 

35. Name the several means commonly employed for 
rendering liquid preparations clear. 

36. Make one plain filter and one plaited filter and return 
both with your recitation paper. 

37. By what means can the passage of fine particles of 
powder through paper filters be prevented in certain cases ? 

38. For what purposes is evaporation employed in 
pharmaceutical processes ? How is it rendered most 
effective ? 

39. What are the practical uses made of distillation in 
pharmacy ? 

40. What kind of a still is best for distilling volatile 
liquids ? 



PHARMACEUTICAL OPERATIONS 289 

41. What is the difference between the Liebig condenser 
and the Mitscherlich condenser ? 

42. Describe the worm-condenser. 

43. Can a still be so made that a separate condenser is 
not necessary ? If so, how ? 

44. By what several means can solids be made to assume 
a crystalline form ? 

45. What is meant by granulation ? 

46. What is the technical term used to designate the 
liquid from which crystals are deposited ? 

47. Define precipitation. 

48. What are the practical uses of crystallization ? 

49. What are the practical uses of precipitation ? 

50. What is meant by the term supernatant liquid ? 

51. How long should a precipitate be washed before it is 
dried? 

52. How is the washing of a precipitate effected ? 

53. What is the difference between physical precipitation 
and chemical precipitation ? 

54. By what means can precipitations be rendered heavy 
instead of light, or fine instead of coarse ? 

55. Draw a figure showing the construction of a Liebig 
condenser. 

56. Make an outline drawing showing the construction of 
a Mitscherlich condenser. 

57. What would you call the kind of chemical reaction by 
which precipitation is produced ? 

58. What are the usual means adopted to produce large 
crystals of water-soluble salts ? 

59. By what means can very small crystals of water-soluble 
salts be secured ? 

60. How would you produce crystals of insoluble volatile 
substances ? 

61. Give three examples of physical precipitation. 



290 A CORRESPONDENCE COURSE IN PHARMACY 

62. Give ten examples of chemical precipitation. 

63. What is contained in the liquid in which a precip- 
itate is produced by chemical reaction, and how can the sub- 
stance contained in that liquid be recovered from it, if 
desired ? 



LESSON NINETEEN 

XXVIII 

The Chemical Constituents of Plant Drugs 

483. The substances contained in plant drugs may be 
classified into groups, as follows: 1, water; 2, cellulose in 
its various forms, the principal of which is woody fiber; 
3, starch in its many forms; 4, pectinous substances; 
5, vegetable mucilage; 6, sugars; 7, albuminoids; 8, fixed 
oils and fats; 9, organic acids ; 10, tannin; 11, bitters, called 
in Latin amara; 12, volatile oils; 13, resins; 14, glucosides; 
15, alkaloids. 

484. Water is contained in all plants. Some fresh plants 
contain over 90 per cent., others much smaller amounts. 

Plant drugs must be dried in order to preserve them. 
The condition in which they are ordinarily employed is that 
called "air-dry." An air-dried drug contains no more 
moisture than it necessarily must contain as usually kept, 
exposed as it is to the ordinary atmosphere. If dried beyond 
that point, it absorbs moisture again ; if it contains more 
than that amount of moisture, it is liable to be damaged by 
mold or fermentation. 

Fresh drugs are also used for making pharmaceutical 
preparations, but whenever this is done, the amount of 
moisture contained in the undried drug must be considered 
in connection with the method of preparation adopted. 

485. Cellulose, starch, pectin, mucilage and sugar are all 
so-called carbohydrates. By the term carbohydrate is 

291 



'-202 A CORRESPONDENCE COURSE IN PHARMACY 

meant an organic substance having the formula or com- 
position C 6 H 10 O 5 , or a multiple of that formula. Some 
carbohydrates differ from this formula, but only by two 
hydrogen atoms and one oxygen atom, added or deducted. 
The carbohydrates have no medicinal action of great 
importance, but some drugs containing starch, and others 
containing mucilage, are employed for the purpose of pre- 
paring demulcent or mucilaginous liquids, to serve as vehicles 
for more potent remedies, or to protect local mucous surfaces. 

486. Cellulose, which exists in plant drugs chiefly as woody 
fiber, is entirely insoluble in all ordinary solvents, such as 
water, alcohol, glycerin, etc. Therefore, cellulose con- 
stitutes a large proportion of the undissolved residue obtained 
when extracts are made of plant organs. 

487. The various classes of constituents of plant drugs 
are contained in the cells and the intercellular spaces in the 
tissues. These cavities are bounded by the cell walls, made 
of the insoluble cellulose. Hence, the cellulose offers more 
or less obstruction to the extraction of soluble substances 
contained in the drugs. This fact renders it necessary to 
grind or powder the plant drugs sufficiently to break down 
the obstruction. 

488. Water has the power to pass through vegetable 
membranes, even when the pores in those membranes are 
extremely minute. This power of liquids to pass through 
vegetable membranes is called osmosis. Its passage out- 
ward is called exosmosis. The current inward is called en- 
dosmosis. We make use of this property of water in our 
pharmaceutical operations, as will be explained in the next 
paragraph. 

489. Certain substances soluble in water may pass through 
vegetable membranes in a state of solution, and this 
phenomenon is called dialysis. Other substances soluble 
in water cannot pass through vegetable membranes, or do 



THE CHEMICAL CONSTITUENTS OF PLANT DEUGS 293 

it so slowly as to be practically undialyzable. We are there- 
fore able to separate dialyzable substances from the undia- 
lyzable substances, even in drugs so coarsely powdered that 
only a small proportion of the cells and intercellular cavities 
are broken into. Therefore, whenever the valuable con- 
stituents of a drug are best dissolved in water, it is not 
necessary to powder the drug finely. Even a piece of whole 
drug will give up a good deal of its dialyzable constituents 
when put in water. For instance, a piece of gentian placed 
in water will very quickly make all of that water bitter. 

490. Alcohol passes through plant membranes so extremely 
slowly that we cannot take any advantage of its slight 
power to do so. We consider it practically unable to 
penetrate plant membranes. Whenever, therefore, the 
valuable constituents of a plant drug are such as require 
alcohol for their solution and extraction, it is necessary 
that the drug shall be powdered finely so that the alcohol 
may come in actual contact with the substances to be dis- 
solved, for the alcohol will only wash off what is on the 
surface of the particles of powder, and will extract nothing 
from the interior of cellular structures. 

491. Starch in its normal condition is entirely insoluble in 
alcohol and in water, but the starch 'in plant drugs is often 
altered starch. It has been changed under the influence of 
heat, moisture and the action of various substances contained 
with the starch in the drug, in such a way that it is not 
insoluble. Altered or partially altered starch is sometimes 
soluble in water to such an extent that when extracted from 
the drug by a very diluted alcohol, it may form a consider- 
able deposit on the bottom of the bottle upon standing for 
some time; for the altered starch, although soluble in water 
and very diluted alcohol, reverts to its normal insoluble 
condition when long in contact with alcohol. Hence, when 
sarsaparilla or licorice root is extracted by percolation with 



291 A CORRESPONDENCE COURSE IN" PHARMACY 

a very diluted alcohol, the liquid extract, although perfectly 
clear or free from solid particles, will, in the course of a few 
weeks, deposit a large layer of white or nearly white starch. 
Starch is altered by water having a temperature above 
60° C. , so that the starch granules burst and a mucilage results. 
From this starch -mucilage the starch cannot be recovered in 
its normal condition. Yet the starch held in the mucilage 
is not, strictly speaking, dissolved; it is simply held in 
suspension, distributed through the liquid uniformly. To 
make starch-mucilage, it is customary to employ one part of 
starch to one hundred parts of water ; but to make a starch- 
paste, one part of starch is necessary with ten parts of water. 

492. To illustrate how the constituents of drugs guide us 
in making pharmaceutical preparations, I may mention that 
some drugs containing a large amount of starch in addition 
to their more important constituents may be treated in 
different ways, according to whether or not we desire the 
product to contain the starch. The pharmacopoeias contain 
an infusion of calumba and also a decoction of calumba. 
The infusion is made with hot water, but the temperature 
is not maintained and hence the starch is not extracted and 
rendered mucilaginous. But the decoction is made by 
boiling the drug in water, and that preparation accordingly 
is thick and demulcent, because it contains the starch. 

Barley, rice, oats and wheat consist largely of starch, and 
decoctions are made of them. Whenever a decoction of 
starch or a starchy drug is made, it is intended that so much 
drug shall be used that the preparation will be sufficiently 
thick. Other preparations are scarcely ever made from 
starchy substances. 

493. Pectin and pectinous substances are water-soluble. 
They resemble mucilage in many respects, but have the 
characteristic property of forming jellies. Apples, currants 
and other fruits form jellies because they contain pectin. 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 295 

Some other fruits, like cherries, do not form jelly because 
they contain an insufficient amount of pectin. The forma- 
tion of the jelly requires the presence of a sufficient amount 
of pectin, and the formation of the jelly is aided by the addi- 
tion of much sugar. 

Some drugs contain pectin. As an example, we may 
mention kino, which contains so much pectin that a tincture 
of kino made with diluted alcohol sometimes changes to a 
solid jelly in the bottle. Pectin is insoluble in alcohol, and 
is therefore not contained in pharmaceutical preparations 
made with strong alcohol. 

494. Mucilage is contained in nearly all plants. It may 
be normal or physiological mucilage, formed in the natural 
growth and life of a plant, or it may be pathological mucilage, 
formed by the breaking down of plant tissues, caused by 
injury. 

We see physiological mucilage in many leaves and in the 
inner bark of plants. We also find it covering the seed-coat 
of flaxseed, quince-seed and some other seeds. 

Pathological mucilage occurs in masses on the trunks and 
branches of certain trees and shrubs, when the bark has been 
perforated by insects. Apple tree gum, peach tree gum, 
cherry tree gum and gums upon other trees of the same 
natural order are familiar. These solid gums are formed 
by the evaporation of the plant-juice exuding through the 
wound made in the bark of the tree by an insect. 

495. There are two classes of gums — the arabin gums and 
the bassorin gums. The arabin gums are completely soluble 
in water; the bassorin gums simply absorb water and swell 
in it to form translucent jellies, but do not dissolve. Gum 
arabic is a typical example of the arabin gums. Tragacanth 
is a typical example of the bassorin gums. A piece of gum 
arabic put in water dissolves completely, forming a mucilage, 
but a piece of tragacanth put in a large amount of water 



296 A CORRESPONDENCE COURSE IN PHARMACY 

simply swells and softens until it has taken up all the water 
it is capable of absorbing, and then forms a gelatinous mass, 
the outlines of which can be readily seen in the water, and 
this gelatinous mass remains distinct from the water about 
it. If the mixture is stirred actively, the jelly is, of course, 
disintegrated, but it does not dissolve, and if the mixture is 
thoroughly shaken in a bottle and then allowed to stand at 
rest, the gelatinous tragacanth separates again. 

496. The word "gum" is so much misused that it perhaps 
ought to be discarded from technical nomenclature. Tech- 
nically, gum is dry mucilage. It is either perfectly soluble 
in water or forms a mucilage with water, even if it is not 
really soluble. Hence, no substance insoluble in water, or 
nearly so, can be a gum. Nevertheless, many resins which 
are entirely insoluble in water are called gums, as, for 
instance, shellac, benzoin, copal, mastic, etc. Gums are 
entirely insoluble in alcohol. For this reason, when alcohol 
is added to a water-solution of any gum, the gum separates 
from the solution, or is precipitated. Aloes, kino and 
catechu are extract-like drugs soluble in diluted alcohol. 
They are therefore not gums, although frequently called so. 
There are, in fact, only two kinds of gums in the pharma- 
copoeia, namely, acacia and tragacanth. 

When a gum or dry mucilage is heated, it becomes drier 
and harder instead of fusing, and when the temperature is 
sufficiently high, the gum is charred but does not ignite so 
as to burn with a flame. Compare this behavior of the gums 
with the properties of resins. 

Dried mucilage or gum undergoes no change when kept 
with ordinary care, but moist gum or a solution or mucilage 
undergoes fermentation when exposed to the air, and muci- 
lage ferments so readily that it can be kept unaltered only a 
few days. 

Acacia and tragacanth are employed pharmaceutically in 



THE CHEMICAL CONSTITUEKTS OF PLANT DRUGS 297 

making pill-masses and other masses cohesive, and also in 
making emulsions. 

The pharmacopoeias contain mucilages made of sassafras 
pith, slippery elm bark, flaxseed, quince-seed and other 
plant drugs containing mucilage of the arabin type. 

When bassorin gum is heated twenty-four hours in water, 
it is rendered soluble. 

The mucilage of acacia of the pharmacopoeia is made by 
dissolving one part of whole acacia in two parts of water. 

497. Sugars of various kinds are contained in many plants 
and plant drags. All sugars are water-soluble. They are 
also soluble, though less freely, in alcohol. 

A weak sugar-solution made with water undergoes fer- 
mentation when exposed to the air, forming alcohol. 
Hence, a small amount of sugar present in an aqueous liquid 
preparation invites fermentation, but when so much sugar 
is added to a watery solution that the solution acquires 
great density, it acts as a preservative, because it excludes 
air. Air is soluble in water, but is not sol able in a dense 
water-solution of other substances. 

Sugar is used to a great extent to sweeten certain pharma- 
ceutical preparations. Medicated syrups are both sweetened 
and preserved by sugar. 

Fresh plant substances and animal substances placed in a 
large amount of sugar are in a measure preserved, especially 
plant tissues, because the sugar takes up the water, and 
water is essential to the changes that cause organic matter 
to decompose. 

Sugar is also used in pharmacy and in medicine as a 
diluent. One class of dilutions ordered by the pharmacopoeia 
is called triturations. These preparations are composed of 
one part of some active medicinal agent mixed with nine 
parts of milk sugar. 

498. The principal sugars of interest to pharmacists are 



298 A CORRESPONDENCE COURSE IN PHARMACY 

cane sugar and milk sugar. Cane sugar, or ordinary white 
sugar, is extensively used. Milk sugar, which is much less 
readily soluble, is employed as a diluent mainly for insoluble 
substances. Starch-sugar, or glucose, is employed in the 
form of a solution, called glucose syrup. Other saccharine 
substances used in pharmacy and medicine are honey and 
manna. 

499. When sugar ferments, it forms alcohol, as has already 
been mentioned, but the process of fermentation ceases as 
soon as 14 per cent of alcohol is contained in the liquid. 
Accordingly, when wine is made from grape juice, the prod- 
uct cannot naturally contain more than 14 per cent of 
alcohol. Any wine containing a larger percentage of alcohol 
has been fortified by the addition of alcohol after the process 
of fermentation. 

Alcohol acts as a preservative. For this reason, many 
liquid pharmaceutical preparations are made with alcohol. 
The principal preparations of this kind are the tinctures and 
the fluid extracts, but other liquid pharmaceutical prepara- 
tions are also preserved by the addition of smaller quantities 
of alcohol. From what has already been said, it is evident 
that any liquid containing fermentable matter must have at 
least 14 per cent of alcohol in it in order to be proof against 
fermentation. Usually 15 per cent or more is added for 
this purpose. 

500. Albuminoids, or vegetable albumins, are contained in 
many plants and drugs. Vegetable albumin is much like 
animal albumin, and the most familiar and striking type of 
animal albumin is the white of egg. It is a colorless, water- 
soluble substance, insoluble in alcohol, and coagulated by 
heat. 

When an egg is boiled or heated to a temperature above 
60° C, the white of the egg becomes a solid, white, insoluble 
substance, which cannot again be changed back to its original 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 299 

soluble condition, and we say that it is coagulated. Alcohol 
has a similar effect upon the white of egg. 

Albumin, when exposed to the air in the presence of 
moisture, putrefies; that is, it undergoes decomposition, 
resulting in the formation of ill-smelling sulphur compounds, 
because all albumin contains sulphur, together with carbon, 
hydrogen, oxygen and nitrogen. The fact that albumin so 
easily undergoes decomposition renders it desirable that 
most pharmaceutical preparations shall not contain it. 
Moreover, if the albumin is present in any considerable 
quantity, it dilutes the preparation unnecessarily. There- 
fore, in making aqueous extracts of plant drugs, the watery 
liquid containing the soluble matters is brought to the boil- 
ing point, or at least to a temperature above 60° C, in 
order to coagulate the albumin, when it forms solid flocculi 
that can be removed by straining, after which the liquid is 
concentrated by evaporation to obtain the solid substances 
free from the water used. Preparations of plant drugs, if 
made with alcohol, cannot contain albumin, since it is not 
soluble in that liquid. 

501. Fixed oils, fats and waxes are contained in seeds 
and various other plant parts. The student will probably 
be surprised to learn that fats and oils and waxes are salts ; 
yet, such is the case. They are compounds formed by 
certain acids with certain bases. The principal acids form- 
ing fats are called oleic acid, palmitic acid and stearic acid. 
The basic function in a fat is performed by an atomic group 
composed of three atoms of carbon and five atoms of hydro- 
gen, C 3 H 5 , called glyceryl. Our familiar glycerin is the 
hydroxide of glyceryl. Other basic groups may also form fats. 

When a strong alkali like potassium hydroxide or sodium 
hydroxide is added to a fixed oil or fat, a soap is formed. 
The fat-acid forms a potassium salt or sodium salt, which 
constitutes the soap, in place of the glyceryl salt, which con- 



300 A CORRESPONDENCE COURSE IN PHARMACY 

stituted the fixed oil or fat. If potassium hydroxide is used, 
soft soap is formed ; if sodium hydroxide is used, hard soap 
is formed. Castile soap consists almost entirely of sodium 
oleate. 

Oleate of glyceryl is called olein. Palmitate of glyceryl is 
palmitin, and stearate of glyceryl is stearin. Olein is per- 
fectly liquid. Olive oil and almond oil consist very largely 
of olein. Palmitin is like a soft ointment and palm oil con- 
tains a good deal of it, so that palmitic acid and palmitin 
are named after palm oil. Stearin is hard. Solid fats are 
solid because they contain a considerable amount of stearin, 
and their hardness is in direct ratio to the percentage of 
stearin. 

Fixed oils are called so because they are not volatile; they 
cannot be distilled. If heated strongly enough, they decom- 
pose. They burn with a smoky flame if the supply of 
oxygen is insufficient, but with a smokeless flame if arrange- 
ments are made to supply an abundance of the oxidizing 
agent. 

Fixed oils, fats and waxes are all absolutely insoluble in 
water. They are all lighter than water. They are soluble 
to some extent in alcohol, more soluble if the alcohol is 
strong. They dissolve freely in ether, chloroform, liquid 
hydrocarbons and volatile oils. Pure fixed oils and fats are 
odorless and colorless, but many of these substances are 
more or less impure, or contain naturally other substances 
that impart color and odor. 

Fixed oils have no action whatever upon vital organs of 
the body, and therefore are very harmless when taken 
internally. In fact, it may be said that their only use 
medicinally depends upon their emollient effect. They 
soften and penetrate the skin so that certain medicinal agents 
can be administered through the medium of ointments and 
cerates applied to the skin, or ointments and cerates are 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 301 

used as local dressings for protection, etc. Castor oil has a 
laxative effect, but that effect is not due to the fixed oil as 
such, but to some other substance held in solution in it. 
This laxative or cathartic substance contained in the castor 
oil abounds in the whole castor oil plant, so that the bruised 
leaves are far more active than castor oil. 

When strong alcohol is used as a menstruum in making a 
pharmaceutical preparation of a plant drug, any fixed oil 
contained in the drug is dissolved by alcohol and may after- 
wards separate, at least in part, from the alcoholic solution 
on standing, and if the alcoholic liquid extract is evaporated 
until a solid mass remains, the fixed oil or fat may be readily 
seen to constitute a part of the residue, and if there is a 
large amount of fat present, it should be removed. There 
are several methods by which fixed oil can be removed in 
preparing solid extracts. One method consists in dissolving 
out the fixed oil with ether before using any other solvent. 
This can be done whenever the valuable constituent of the 
drug is not soluble in ether. Another method consists in 
using as a menstruum or solvent a liquid which, while 
extracting the valuable constituents, will not dissolve the 
fixed oil or fat. A third method consists in extracting the 
grease, together with the active constituents, and then 
separating the grease afterwards. 

502. Organic acids occur in abundance in some fruits. 
Small amounts of numerous kinds of organic acids occur 
very generally in plants. There is probably not a plant 
growing that does not contain one or more kinds of organic 
acid. Among the organic acids that occur in fruits and 
other plant parts in considerable quantities, we may mention 
oxalic acid, tartaric acid, citric acid and malic acid. None 
of these acids has any important medicinal action, and 
probably not one plant drug owes its medicinal value to any 
organic acid, unless it be what is called a * 'resin-acid." 



302 A CORRESPONDENCE COURSE IN PHARMACY 

503. We have now enumerated all the classes of plant 
constituents without decided medicinal action. They are 
commonly referred to as inert constituents of the plant 
drugs. In making pharmaceutical preparations and partic- 
ularly in making solid extracts, the aim of the pharmacist is 
to eliminate from his products all the inert constituents, or 
as great a proportion of them as possible, in order that the 
preparation may be as concentrated as practicable. 

504. Tannin is a peculiar substance contained in almost 
every growing plant, and, therefore, also in almost every 
plant drug. When extracted from the plant and separated 
from other substances, tannin is a dry solid of a very light 
yellow color. It is soft, friable, and soluble in water, 
alcohol and glycerin. It is insoluble in absolute ether, but 
soluble in ether saturated with water ; in fact, it is usually 
extracted from nutgall with an ether containing 10 per cent 
of water in solution. Tannin is astringent, and all drugs 
containing a sufficient amount of tannin are also astringent 
and used for their astringent properties, unless they also 
contain other and much more important constituents. An 
astringent drug, in order to be effective, ought to contain 
not less than 10 per cent of tannin. Several astringent 
drugs contain more than 20 per cent and nutgall contains 
from 50 to 60 per cent. 

Tannin is named so because it has the property of tan- 
ning raw hide, converting it into leather. But there are 
two classes of tannins, and only the tannins of one of those 
classes will make leather. Physiological tannins are the 
tannins naturally contained in live plants. It is found chiefly 
in barks. Physiological tannin has the property of forming 
leather. Pathological tannin is the tannin formed in large 
quantities in galls or excrescences on the barks and leaves 
of trees when stung by insects. The nutgall is formed in 
such a way. When the insect stings through the bark, there 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 303 

is a flow of sap to the spot, and a gall is gradually formed 
surrounding the egg laid I t the insect. 

Tannin forms insoluble compounds with a large number 
of other substances. It therefore makes precipitates in 
solutions containing gelatin, mucilage, alkaloidal salts, 
metallic salts, etc. With iron compounds dissolved in water, 
liquids containing tannin form ink. Hence, the tincture of 
chloride of iron which is so much used by physicians always 
forms an inky mixture with the tinctures of nearly all plant 
drugs, because the tinctures of plant drugs contain tannin. 

Tannin in water-solution rapidly undergoes decomposition, 
but alcoholic liquid preparations containing tannin can be 
kept a reasonable length of time without serious deteriora- 
tion. Fluid extracts and tinctures made out of astringent 
drugs are all made with diluted alcohol containing a certain 
amount of glycerin, because the tannin compounds insoluble 
in water and in alcohol are many of them soluble in glycerin, 
so that the addition of glycerin to the preparation prevents 
precipitation. 

505. Amara, or bitters, are a miscellaneous class of plant 
constituents of no great importance. They are sometimes 
called neutral principles, simply because they are neither 
acids nor bases. It is impossible to describe them, because 
they have few properties in common. Many of them are 
water-soluble, but scarcely soluble in alcohol. Others are 
freely alcohol-soluble and scarcely soluble in water. Most 
of them dissolve sufficiently well in a mixture of alcohol and 
water, or, in other words, in diluted alcohol. Hence, both 
tinctures and fluid extracts of bitter drugs or simple 
stomachic tonics are made with diluted alcohol, and some of 
the solid extracts of such drugs are made with diluted 
alcohol, while others are made with water. 

The dose of an amarum may be said to be altogether 
indefinite. A quantity sufficient to produce a bitter impres- 



304 A CORRESPONDENCE COURSE IN PHARMACY 

sion to the taste is usually a sufficient dose, and a much 
larger dose will probably produce no greater effect. Hence, 
a very large dose of a simple bitter stomachic tonic cannot 
do any harm, beyond the inconvenience of the bitter taste. 

506. Volatile oils are a very miscellaneous class of sub- 
stances, too. The name volatile oil is quite misleading. The 
word volatile usually suggests that volatile oils are excep- 
tionally volatile, whereas they are much less volatile than 
water, for water boils at 100° C, whereas the average boil- 
ing point of volatile oils is above 120° 0. The term "vola- 
tile oil" suggests that these substances resemble fixed oils, 
whereas they do not resemble fixed oils any more than they 
resemble a great many other liquids. Volatile oils are in 
fact radically different from fixed oils, not only in that the 
volatile oil is distillable while the fixed oil cannot be distilled, 
but also in that volatile oils are always odorous, whereas fixed 
oils, when pure, are odorless. The volatile oils have a 
pungent or hot taste, whereas fixed oils have a very bland 
taste, if any. Volatile oils burn fiercely with a smoky flame, 
even in an abundant supply of air or oxygen. Volatile oils 
dissolve to a slight extent in water, while fixed oils are 
insoluble in water. The volatile oils dissolve very freely in 
alcohol, whereas fixed oils dissolve only to a limited extent 
in that solvent. Volatile oils do not contain any fat-acids 
nor any glyceryl compounds, whereas fixed oils are composed 
of nothing else. 

The most common constituents of volatile oils are hydro- 
carbons of the formula C 5 H 8 or a multiple of 5 H 8 , such as 
O 10 H 16 or C 15 H 24 or C 20 H 32 . The hydrocarbons having the 
formula C 10 H 16 are called terpenes ; those of the composition 
C 5 H 8 are called semi-terpenes ; those having the formula 
C 15 H 24 are called sesqui-terpenes, and those of the composition 
C 20 H 32 are called diterpenes or double terpenes. These 
hydrocarbons are liquids. They are oxidized on exposure 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 305 

to air and form oxidation products which are also usually 
contained in greater or less proportion in all volatile oils. 
The oxidation products are some of them camphors, while 
others are resins. 

Volatile oils are nearly all liquids at common temperatures, 
but some of them solidify at but a few degrees below the 
ordinary room temperature. When a volatile oil is placed 
in a cold room, a solid substance may crystallize out from it. 
In other words, some volatile oils are separable into a liquid 
portion called the elaeopten and a solid portion called the 
stearopten. The elaeopten contains most, if not all, of the 
hydrocarbons, while the stearopten contains most, if not all, 
of the oxidation products, or compounds containing oxygen. 

Scarcely a single plant or flower having a distinctive odor 
is free from volatile oil, to which that odor is due. The 
odorous substance in sweet clover is not a volatile oil, but 
contains the odorous crystallizable substance called coumarin. 
But odorous substances of plant origin that are not volatile 
oils are rare. 

The odors of volatile oils are so powerful that an extremely 
minute amount will impart a characteristic odor to the 
plant, flower or drug. Aloes is a drug having an intensely 
strong, disagreeable odor, and that odor is due to volatile 
oil. The amount of volatile oil in aloes is so small that it 
takes three hundred pounds of the drug to make a single 
ounce of the volatile oil. 

Some flowers having a powerful and agreeable fragrance 
contain so little volatile oil that it is extremely difficult to 
extract it, and perfumes of such flowers are made not from 
the volatile oils, but from the flowers themselves. 

It has been found that volatile oils containing oxygen com- 
pounds have more pronounced odors than volatile oils that do 
not contain them, or that contain smaller amounts of the 
oxygen compounds. It is said that certain volatile oils con- 



306 A CORRESPONDENCE COURSE IN PHARMACY 

sisting almost entirely of hydrocarbons without any oxygen 
have no odor at all, although they are generally believed to be 
very fragrant. It is thought, for instance, that oil of lemon 
has no odor, but that when the vapor of oil of lemon mixes 
with air before it reaches the nostrils, the odor perceived is 
created by the oxidation resulting from the admixture of air. 
Oil of cloves has a powerful odor because it contains a 
considerable quantity of oxygen compounds. Certain other 
volatile oils contain sulphur compounds, and also cyanogen 
compounds, and they have very strong, disagreeable odors. 

All volatile oils are stimulants. All of them are diuretics. 
Some of them are anthelmintics. Many oils are so irritant as 
to be rubefacient when applied externally. Other medicinal 
uses of volatile oils are comparatively unimportant. 

Water-solutions of volatile oils contain usually much less 
than one-tenth of 1 per cent, of volatile oil, although they 
are saturated, but this small amount of volatile oil renders 
the water both fragrant and pungent. 

All of our spices contain volatile oils and most of them 
contain, in addition, resins formed by the oxidation of the 
volatile oils. 

Since alcohol is the most effective solvent for volatile oils, 
the pharmaceutical preparations made out of plant drugs 
containing volatile oils are generally made with a strongly 
alcoholic menstruum, and diluted alcohol is used only when 
the quantity of volatile oil in the drug is comparatively small. 

Drugs containing volatile oils as their only valuable 
medicinal constituents are called aromatic stimulants. 

If a mixture of alcohol and volatile oil is put in a gradu- 
ated glass tube and water is added in large quantity, the 
alcohol leaves the volatile oil and enters solution in the 
water, so that the volume of the volatile oil is diminished 
by j ust the amount of alcohol it contained. The adulteration 
of volatile oils with alcohol is easily detected in this way, 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 307 

and even the quantity of adulterant may be accurately 
determined. 

507. Resins are oxidation products of volatile oils, and as 
the volatile oils are usually mixtures of several substances, 
the resulting resins are also mixtures. Most of the resins 
are dry solids, but some of them are soft solids, or semi-solids. 

All resins are insoluble in water, but perfectly soluble in 
alcohol. Some resins are also soluble in ether and in chloro- 
form, and all resins are soluble in volatile oils. 

Eesins are in some respects like feeble acids. While not 
exhibiting strongly acid properties, they form water-soluble 
compounds with the alkalies and with the alkaline earths. 
Eesin soaps are made from alkalies and resin instead of alkalies 
and fats. The resin-soaps have detergent properties like 
the true soaps, but they are easily decomposed in boiling 
water. 

Eesins ignite readily and burn with a smoky flame, owing 
to the large amount of carbon they contain which is not 
consumed. They melt when heated and do not decompose 
until ignited. 

Soft resins are usually acrid, but some dry resins are also 
acrid to such an extent that when applied to the skin they 
raise blisters. The soft resins cannot be dried so as to 
become hard. 

Pharmaceutically, the resins are used in making plas- 
ters, cerates and ointments. Industrially, the resins are 
used in making varnishes, sealing wax and various other 
products. 

Irritant resins usually have a cathartic action, and most, 
if not all, of the plant cathartics contain either resins or 
resin-compounds, to which their medicinal action is due. 
Some resins which are hard and dry do not dissolve in the 
stomach, but pass beyond it and are dissolved only when 
they come in contact with the alkaline bile. For this reason 



308 A CORRESPONDENCE COURSE IN PHARMACY 

physicians sometimes order hard, dry, inert resins added to 
pills in order to make them slowly active. 

Tinctures and fluid extracts of resinous drugs are, of 
course, prepared with strong alcohol. 

508. Glucosides are named after glucose, and they have 
received the name glucoside because, when they decompose, 
one of the products of the decomposition is sugar. They 
are very unstable as a rule, decomposing easily when heated 
in water in the presence of a little acid or in the presence of 
certain kinds of ferments. 

The first glucoside to be definitely described as a typical 
substance of this class was amygdalin. Amygdalin is the 
bitter substance contained in bitter almonds, and it is 
decomposed when water is added to the bitter almond, the 
decomposition being effected through the action of the white 
fleshy substance of the almond, which is called emulsin or 
synaptase, which is a nitrogen compound acting as a ferment. 
As long as the bitter almond is dry, the amygdalin remains 
intact, but upon the addition of water, it all decomposes 
within twenty or thirty minutes, and then splits up into 
volatile oil of bitter almond, hydrocyanic acid and sugar. 
Amygdalin exists also in peach kernels, cherry seeds and a 
number of other seeds, which are therefore poisonous. They 
do not contain any poison, but they contain the glucoside 
amygdalin, which gives rise to the formation of the highly 
poisonous hydrocyanic acid as soon as wetted with water. 

No general description of glucosides beyond what little 
has already been mentioned can be made, because they are 
so miscellaneous in character. Some of them are soluble 
in water, but not in alcohol, while others are soluble in 
alcohol, but not in water. A large number of the glucosides 
are either poisonous or form poisons when decomposed. In 
fact, two-thirds of all poisonous plant drugs contain alkaloids, 
and the remaining one-third contain glucosides. 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 309 

Many of the glucosides contained in drugs have a decided 
action on the circulatory system, affecting the heart 
strongly. 

Tinctures and fluid extracts are made of drugs containing 
glucosides, but solid extracts are not made of all glucosidal 
drugs, because of the unstable character of the glucosides. 

509. Alkaloids are chemical compounds containing carbon, 
hydrogen and nitrogen, or carbon, hydrogen, nitrogen and 
oxygen, having the power of neutralizing acids to form salts 
and of turning certain red vegetable colors blue. They are 
called alkaloids because they resemble the alkalies in the 
properties just mentioned. They are also called vegetable 
bases. 

When the alkaloids form salts with acids they act in the 
same manner as ammonia, in that the entire molecule of the 
alkaloid enters into combination with the entire molecule of 
the acid by a rearrangement of the atomic linking. When 
ammonia, H 3 N, reacts with hydrogen chloride, HC1, the 
compound formed is H 4 NC1, from which it will be seen that 
the hydrogen and the chlorine of the hydrogen chloride are 
separated from each other by the nitrogen of the ammonia. 
When ammonia reacts with nitric acid in ammonium nitrate, 
H 4 NN0 3 , it will also be seen that the nitrogen of the 
ammonia separates the hydrogen of the nitric acid from its 
N0 3 . Alkaloids and acids form salts in a similar way. For 
this reason alkaloids have sometimes been called compound 
ammonias. 

Alkaloids are always poisonous, and some of them are so 
potent that the customary dose may be less than the two- 
hundredth part of a grain. 

Examples of alkaloids are found in quinine, morphine, 
strychnine, cocaine and caffeine. It is true that quinine 
and caffeine and some other alkaloids are not generally looked 
upon as being poisonous, but if a considerable quantity be 



310 A CORRESPONDENCE COURSE IN PHARMACY 

taken internally of either of them, alarming effects will 
undoubtedly be produced. From what has been said, it will 
be apparent that a very large number of our most important 
plant drugs contain alkaloids as their principal active 
constituents. The English names of alkaloids are in this 
country given the ending ine, and the corresponding Latinic 
titles in the pharmacopoeias have the ending ina. 

There are two classes of alkaloids — the ternary alkaloids 
and the quaternary alkaloids. The ternary alkaloids are 
called so because they contain only the three elements 
carbon, hydrogen and nitrogen. They are volatile, so that 
they can be distilled or vaporized without decomposition, 
have a strong odor and are generally liquid. The quaternary 
alkaloids are called so because they contain four elements, 
carbon, hydrogen, nitrogen and oxygen. These are solids. 
Very few of them can be vaporized without decomposition, 
and they have no odor. The volatile alkaloids are few in 
number in comparison with the solid alkaloids. 

The volatile alkaloids are soluble in water as well as in 
alcohol, and hence preparations of plant drugs containing 
volatile alkaloids may be made either with alcohol or water, 
or a mixture of the two. But the alkaloids containing 
oxygen usually require a strongly alcoholic menstruum, 
because they are rarely soluble in water. 

Alkaloids seldom occur in the plants and plant drugs 
uncombined with acids. They are usually found in com- 
bination with peculiar organic acids which, like the alkaloids 
themselves, are rarely found in more than one plant genus. 
The salts which the alkaloids form with the organic acids 
referred to are generally alcohol-soluble, and to a much less 
extent water-soluble. But the alkaloids can be extracted 
from the plant drugs and separated from all other substances 
and then converted into salts witli the ordinary acids. These 
salts are frequently freely water-soluble. From what has 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 311 

been said it will be understood that the alkaloids of plant 
drugs may be extracted with water to which has been added 
some acid forming a water-soluble salt with the particular 
alkaloid to be dissolved, or the drug may be mixed with an 
alkali which liberates the alkaloid from its natural salt, after 
which alcohol, ether, chloroform, petroleum spirit or some 
other suitable solvent for the free alkaloid may be used. 
But these are chemical methods of extracting alkaloids. 
The pharmaceutical method of extracting them consists in 
using an alcoholic menstruum which will extract the natural 
alkaloidal compound without chemical alteration. 

510. The active principles of plant drugs belong to the 
classes described as tannins, bitters, volatile oils, resins, 
glucosides and alkaloids, and any plant drug containing no 
substance belonging to either of those classes is not likely to 
possess any medicinal value. The activity of any particular 
drug may be due to only one substance or it may be due to 
two or three or several substances. 

511. The chemical constituents found in plant drugs are 
generally formed in the plant during its life, but several 
important valuable constituents of drugs are formed after 
the death of the plant, by chemical changes in the natural 
constituents. Opium, for instance, is a drug formed by 
drying the fluid that exudes from poppy capsules when full 
grown and just before they ripen, through incisions made in 
the capsules. No morphine or only traces of it or of any 
other alkaloids have been found in the poppy capsules, but 
the opium, when finished by drying the poppy juice in the 
sun, may contain over 20 per cent, of total alkaloids. 
Another illustration is furnished by the common drug called 
frangula, which, when just gathered, is a violent griping 
cathartic and even emetic, but which after having been kept 
for a year or two becomes a mild laxative, the cathartic 
substances being decomposed and giving place to decom- 



312 A CORRESPONDENCE COURSE IN PHARMACY 

position products having a milder action. Some drugs are 
used in the fresh condition before the natural constituents 
undergo alteration, while other drugs are not used until after 
they have become modified by the chemical changes referred 
to. It is further to be understood that these chemical 
changes in the constituents of drugs continue through a 
long time, so that probably all plant drugs deteriorate when 
kept too long, and many of the plant drugs contain such 
unstable active principles that they cannot be preserved 
unaltered even for a few months. A fresh supply of an 
unstable plant drug can, of course, be obtained only once a 
year, and such drugs should accordingly be procured by 
the pharmacist at the right season, that is, immediately 
after the new crop comes into the market. Such drugs 
should be preserved with the greatest care. Very few drugs 
are comparatively permanent, so that they remain in good 
condition as long as two years. 



Test Questions 

1. What is a carbohydrate ? 

2. Which of the class of carbohydrates are water-soluble ? 

3. What is exosmosis ? 

4. What advantage can be taken of dialyzation in the 
extraction of the constituents of drugs ? 

5. Which of the several classes of chemical constituents 
of drugs are dialyzable ? 

6. Name a solvent for starch in its normal condition. 

7. What is meant in pharmacy by the expression * 'altered 
starch"? 

8. What kinds of drugs are employed for making 
demulcent decoctions and what drugs for mucilaginous 
infusions ? 



THE CHEMICAL CONSTITUENTS OF PLANT DRUGS 313 

9. Name some substances containing normal starch and 
some other substances containing altered starch. 

10. What kind of a menstruum can be used on plant drugs 
which will not extract carbohydrates ? 

11. What is the cause of gelatinization in certain liquid 
pharmaceutical preparations ? 

12. What is a gum ? 

13. Name all of the gums you can think of. 

14. What is the difference between arabin and bassorin ? 

15. Can you name some gums soluble in alcohol ? 

16. If you have a liquid extract containing mucilage in 
solution, how can you remove that mucilage from the liquid ? 

17. What are the pharmaceutical uses of the official gums ? 

18. In what parts of plants is physiological mucilage 
usually found ? 

19. In view of the fact that mucilage ferments so easily, 
how can drugs containing mucilage be preserved ? 

20. In what manner does sugar act as a preservative of 
water-solutions of fermentable substances ? 

21. What are the pharmaceutical uses of sugar? 

22. What proportion of alcohol must be contained in a 
solution of fermentable matter in order to prevent fer- 
mentation ? 

23. Mention some plant constituents contained in aqueous 
liquid extracts which are not contained in alcoholic liquid 
extracts. 

24. Name some plant constituents contained in alcoholic 
liquid extracts which are not contained in aqueous extracts. 

25. Name some plant constituents which are soluble both 
in water and in alcohol. 

26. At what temperature does starch become pasty in 
water ? 

27. At what temperature does albumin coagulate ? 

28. Which kind of a liquid extract contains the most 



314 A CORRESPONDENCE COURSE IN PHARMACY 

albumin, a liquid extract -made with cold water or with 
boiling water or with alcohol ? 

29. Which preparation contains the most starch, one made 
with cold water, boiling water or alcohol ? 

30. Can albumin in solution be separated from a liquid 
extract ? If so, how ? 

31. What is glyceryl hydroxide commonly called ? 

32. Can you mention any other common glyceryl com- 
pounds ? 

33. What is hard soap and what is soft soap ? 

34. Name the most common fat-acids. 

35. What is the chemical composition of olive oil, lard, 
tallow and cottonseed oil ? 

36. What is stearin ? 

37. What are the principal physical differences between 
olein, palmitin and stearin ? 

38. What liquid pharmaceutical preparations are most 
liable to contain fixed oils, those made with water, with 
diluted alcohol, with strong alcohol or with ether ? 

39. What are the pharmaceutical and medicinal uses of 
fixed oils ? 

40. What parts of plants contain fixed oil more frequently 
than other plant parts ? 

41. Can a solid extract be made from a plant drug con- 
taining fixed oil without obtaining a product mixed with 
grease ? If so, how ? 

42. What are the best solvents for fixed oils ? 

43. What is tannin ? 

44. What are its most characteristic properties ? 

45. Name three different solvents for tannin. 

46. What is the most notable difference between physio- 
logical tannin and pathological tannin ? 

47. What kinds of fluid extracts and tinctures are most 
liable to contain precipitates formed on standing ? 



THE CHEMICAL CONSTITUENTS OF PLANT DEUGS 315 

48. What is meant by an amarum ? 

49. What menstruum is commonly employed in making 
tinctures of drugs containing amara ? 

50. What menstruum is commonly employed in making 
fluid extracts of drugs containing volatile oils ? 

51. What menstruum is commonly employed in making 
fluid extracts of drugs containing tannin ? 

52. Enumerate the differences you can think of between 
volatile oils and fixed oils. 

53. How would you make a solid extract of a drug con- 
taining volatile oil as its only active constituent ? 

54. What are the most common constituents of volatile 
oils ? 

55. Do you think you can discover tannin in a plant drug 
without a chemical examination of it ? 

56. Do you think you can discover volatile oil in a plant 
drug without separating the volatile oil or detecting it by 
chemical means ? 

57. What is the difference between a carbohydrate and a 
hydrocarbon ? 

58. What volatile oils have the strongest odors? 

59. What is the general physiological and therapeutic 
action of volatile oils ? 

60. What volatile oils produce a grease spot on clean 
white unsized paper ? 

61. What are the best solvents for volatile oils ? 

62. What are volatile oils liable to contain besides hydro- 
carbons and camphors ? 

63. What are the constituents contained in aromatic 
astringents ; in astringent bitters ; in aromatic bitters ? 

64. By what means can you detect alcohol in a volatile oil 
adulterated with that liquid ? 

65. What are the solutions of volatile oils in water 
called ? 



316 A CORRESPONDENCE COURSE IN PHARMACY 

66. Why are resins usually found together with volatile 
oils in plants ? 

67. What are the differences between gums and resins ? 

68. What are the pharmaceutical uses of inert resins ? 

69. What are the medicinal effects most common in resins 
and resin compounds ? Why does potash lye dissolve resin ? 

70. Bitter almond is the source of expressed oil of almond, 
as well as of volatile oil of bitter almond and amygdalin. 
The amygdalin is soluble both in hot alcohol and in water. 
W r hat is the best way to extract the amygdalin from the bitter 
almond ? What is amygdalin ? 

71. How can you separate the fixed oil of bitter almond 
without having that fixed oil contaminated with amygdalin ? 

72. How can you make volatile oil of bitter almond and 
subsequently also amygdalin out of the same lot of bitter 
almonds ? 

73. What are usually the active constituents of poisonous 
plant drugs ? What makes peach kernels poisonous ? 

74. What differences can you mention in the chemical 
properties of glucosides and alkaloids ? 

75. Give the origin of the words glucoside and alkaloid. 

76. In what respects do the alkaloids resemble ammonia? 

77. What is the difference between a ternary alkaloid and 
a quaternary alkaloid ? 

78. Are any alkaloids in the free state water-soluble ? 

79. What class of alkaloids are alcohol-soluble ? 

80. What are the best solvents for making liquid extracts 
of alkaloidal drugs ? 

81. What are the most common chemical processes of 
extraction of alkaloids from drugs ? 

82. In what form do the alkaloids usually occur in plant 
drugs ? How long should plant drugs be kept before they 
are used ? 



LESSON TWENTY 

XXIX 

Pharmaceutical Preparations 

-512. The materials out of which pharmaceutical prepara- 
tions are made may be definite chemical compounds or 
simple elements, or they may be mixtures of two or more 
substances. 

Chemical preparations are those made by processes result- 
ing in the formation of new substances, or, in other words, 
processes involving chemical reactions. 

Galenical preparations are preparations made by processes 
not involving any chemical changes. The Galenical prepara- 
tions may be simply mechanical mixtures of the ingredients, 
or they may be solutions or extracts. Organic drugs are of 
such a complex character that their pharmacy is much less 
simple than that of definite chemical compounds. The 
Galenical preparations of plant drugs generally take the form 
of liquid or solid extracts, the object being to present the 
medicinal constituents of the drug in the most concentrated 
and convenient form. 

513. The classification of pharmaceutical preparations may 
be based upon various considerations. Probably the most 
practical and convenient classification is the following: 

1. Dry and semi-solid preparations for internal use, made 
by processes not involving extraction. These preparations 
include species, powders, triturations, confections and electu- 
aries, masses, troches and pills. 

317 



318 A CORRESPONDENCE COURSE IN PHARMACY 

2. Dry and semi-solid preparations for external use, includ- 
ing poultices, ointments, cerates, plasters and suppositories. 

3. Liquid preparations for internal use, not made by proc- 
esses of extraction, including solutions, waters, mucilages, 
syrups, glycerites, mixtures, emulsions and spirits. 

4. Liquid preparations for external use, including lotions, 
gargles, injections, liniments, etc. 

5. Liquid extracts, including infusions, decoctions, vine- 
gars, tinctures, wines and fluid extracts. 

6. Solid and semi-solid preparations made by processes of 
extraction, including solid -extracts, oleoresins and pre- 
cipitated resins. 

XXX 

Solid Preparations Not Made by Extraction 

514. Species are teas made of mixed plant drugs, very 
coarsely cut or crushed. Such preparations are not common 
in America. Breast teas, laxative teas, bitters and stimu- 
lant teas are among the most common. 

515. Powders. Compound powders are made by triturat- 
ing together two or more substances, so as to obtain a prod- 
uct in the pulverulent form. If the ingredients can be 
each in fine powder before being mixed, the process is very 
simple. But when one of the substances is a liquid or moist 
solid, it must be triturated with one or another of the dry 
ingredients in order to reduce it to a state of powder. When 
there is not a sufficient quantity of dry substance, it may be 
necessary after making the mixture to subject it to a drying 
process before finishing the pulverization. If the ingredients 
are nearly equal proportions, they may be mixed all at once, 
but if one ingredient is to be used in very small quantity and 
the other is several times as bulky, the ingredients used in 
large proportion should be divided and an intimate mixture 



SOLID PREPARATIONS NOT MADE BY EXTRACTION 319 

made after adding each consecutive portion to the other ingre- 
dient before the next portion is added. When one or more of 
the ingredients are of such character as to adhere to the 
mortar and pestle when triturated under pressure, the 
trituration should be effected with as little force as possible. 
When the ingredients are such as have a tendency to act 
upon each other chemically, they should also be mixed 
lightly or without pressure, in order to avoid the chemical 
reaction as far as practicable. When potent substances are 
to be diluted in the form of powder, the diluents employed 
may be cane sugar, milk sugar, starch, acacia, tragacanth, 
marshmallow root, or other inert powders. 

516. Triturations are powders made out of potent remedies 
with nine times their weight of milk sugar. 

517. Confections and electuaries are soft solid mixtures, 
made by mixing powders or solid extracts, or both, with syrup 
or honey. These preparations are intended to be sufficiently 
sweetened so that they may be taken without difficulty. 
Very few such preparations are now used. 

518. Masses. Confections and electuaries are, of course, 
masses, but the title massa used in the pharmacopoeia 
means a mass of such consistency that pills can be made out 
of it. The manner in which ingredients are massed for 
making pills and troches will be described later. 

519. Troches or lozenges or tablets are hard, dry pieces of 
medicinal substances weighing from two or three grains up 
to thirty grains. They contain either a large amount of 
sugar or in its place a sufficient quantity of extract of licorice 
to make them less disagreeable to the taste than the unsweet- 
ened medicinal agents usually are. In the preparation of 
troches, etc., the ingredients are, if possible, first reduced to 
a uniform mixture in the state of powder. A moist excipient 
is then added to mass the powder together, or to make it 
cohere so as to form a well-mixed mass which can be rolled 




320 A CORRESPONDENCE COURSE IN PHARMACY 

out into a cake of uniform thickness, out of which the 
tablets or troches are cut by means of a lozenge-cutter. The 
troches are most commonly circular disks, but they may be 
oblong, octagonal and of various other forms. They are 
usually dried so as to become hard, unless they contain 
extract of licorice, in which case they are not always entirely 
dry. Troches are often flavored with volatile oils or with 
aromatic waters. 

520. Pills are small masses of mixed medicinal agents, 
usually of spherical form or oval, weighing from one grain 

to five grains, or from sixty to three hun- 
dred milligrams. 

In making pills, the ingredients are 
mixed uniformly in the same manner as 
medicinal substances are mixed in mak- 
ing compound powders, confections, 
sectional view of masses and troches, and the massing is 

A PILL MORTAR 1 ° 

accomplished in such a way that the pills 
when formed out of the mass may be sufficiently firm to 
retain their shape. 

The pills when finished should be either entirely soluble 
in the fluids of the stomach or they should contain enough 
soluble matter to become disintegrated when wetted. 
Pills which are very hard and almost insoluble are use- 
less, and the pharmacist must choose his excipients for pill- 
masses in such a way as to avoid the formation of insoluble 
pills. 

521. The excipients employed in making pill-masses 
include both solids and liquids. If. the other ingredients 
make a soft mass, it is, of course, necessary to add a dry 
excipient to give the mass the right consistence. While the 
mass should be somewhat plastic in order that it may be 
comparatively easy to form it into perfectly round pills, it 
is also necessary that the mass shall be sufficiently cohesive 



SOLID PREPARATIONS NOT MADE BY EXTRACTION 321 

and firm so that the pills may not flatten after they have 
been finished. 

To stiffen a soft mass, the following dry excipients will be 
found most useful: 

Powdered slippery elm lark is useful, because it is highly 
absorbent and fibrous and contains very little soluble matter. 

Poivdered licorice root and powdered altlma are also 
fibrous and absorbent, but less useful than the slippery elm 
bark, because they contain considerable amounts of soluble 
constituents. 

Starch may also be used to stiffen pill-masses, but it is 
not absorbent and hence somewhat larger quantities must 
be employed of starch than are necessary of such a substance 
as slippery elm bark. 

Magnesium carbonate is an entirely insoluble but absorbent 
substance that can be used to advantage in soft pill-masses 
containing volatile oils or oleoresins. 

None of the dry substances so far mentioned are adhesive. 
The adhesive dry excipients most suitable for making pill- 
masses are powdered tragacanth and powdered extract of 
licorice, but tragacanth Ms so far superior to all other dry 
substances rendered adhesive when moistened that it is 
almost invariably used. Very small amounts of traga- 
canth are usually sufficient to render a pill-mass cohesive, 
when the mass contains enough moisture to develop the 
adhesive quality of the tragacanth. Tragacanth acts slowly, 
so that the operator should add it very gradually and take 
time to observe the results before adding any more. A pill- 
mass that is but very slightly too soft can generally be 
rendered firm by the addition of a very small amount of 
tragacanth. When acacia enters into pill-masses and the 
quantity used is considerable, the result is usually a mass 
that becomes very hard on drying. 

Milk sugar is sometimes introduced into pill-masses to give 



322 A CORRESPONDENCE COURSE IN PHARMACY 

bulk to them or to dilute some very potent substance, but 
it is not enrployed to stiffen soft masses. 

The wet or moist excipients most common are water, 
alcohol, glycerin, glucose, syrup and mucilage of tragacanth. 
When the dry ingredients of a pill-mass contain any sub- 
stance which becomes adhesive as soon as moistened with its 
appropriate solvent, then the addition of that solvent is 
generally sufficient to mass the whole mixture. Extractive 
matter when moistened is always adhesive. Hence, when 
the extractive is water-soluble, the addition of a little water 
will suffice to form the mass, or if the extract is alcohol- 
soluble, we may add alcohol or diluted alcohol, instead of 
water, to develop sufficient adhesiveness to make the mass 
cohesive. 

Glycerin is added in pill-masses solely to prevent them 
from becoming too dry and hard. When too small an amount 
of glycerin is added and the mass contains water, the water 
and glycerin evaporate together, and the pill may after all 
become hard. But a mixture of equal parts of water and 
glycerin or of two parts of water and one part of glycerin 
may be advantageously employed, because when the water 
evaporates enough glycerin will remain to keep the pills from 
becoming too hard. 

Glucose-syrup is so sticky that it is employed in cases 
where the ingredients of the mass are of such a nature as to 
form crumbly masses with less adhesive excipients. 

The student will understand that moist ingredients require 
dry excipients, and dry ingredients require moist excipients, 
and that adhesive materials require only non-adhesive excip- 
ients, while non-adhesive materials require adhesive ex- 
cipients. 

522. Pills should never be less than one grain in tveight. 
If the materials ordered in a prescription are insufficient to 
give each pill the requisite weight, inert excipients are added 



SOLID PREPARATIONS NOT MADE BY EXTRACTION 323 

to increase the mass so that each pill will weigh at least one 
grain. Pills of the size of from two to three grains are more 
readily swallowed than either smaller or larger ones. 

It occasionally happens that a presciiber inadvertently 
orders pills too large to be conveniently taken. In such 
cases, the pharmacist should consult the prescriber and obtain 
permission to divide the mass into twice as many pills or 
even three times as many, in order to obviate the difficulty. 

Pills weighing only one grain are generally called 
granules. 

Pills coated with sugar or various kinds of gelatin coating 
are now manufactured on a large scale, and all the pills 
commonly prescribed can be had already prepared and coated. 
The coatings should either be completely soluble in tepid 
water or should at least become disintegrated, and the pill- 
mass itself should also be either soluble or should fall apart 
when put in tepid water. 

523. Cataplasms, or poultices, are not often prepared by the 
pharmacist. The most common cataplasms are flaxseed 
poultices and mustard plasters. 

Flaxseed poultice is made by first mixing the ground 
flaxseed with a little cold water, mixing well so as to break 
up all lumps, then adding the requisite amount of boiling 
water and heating the mixture until the starch in the flaxseed 
becomes sufficiently pasty so that the resulting cataplasm 
has the right consistence. 

Mustard plaster is best made by mixing the ground 
mustard by trituration with tepid water. The water causes 
the formation of the irritant volatile oil which renders the 
mustard plaster, effective as a rubefacient. If it is desired 
to make the mustard plaster milder in its action, the ground 
mustard is diluted with white flour, corn meal, or ground 
flaxseed before being made into a cataplasm, or a cataplasm 
of pure ground mustard and tepid water is mixed with a 



324 A CORRESPONDENCE COURSE IN PHARMACY 

separately prepared poultice of flaxseed or corn meal. In 
making a mustard plaster, boiling water should never be 
used, because it coagulates one of the constituents of the 
mustard which causes the formation of the volatile oil, and 
moreover causes the volatile oil to vaporize and be lost. 
Neither should alcohol be used in making mustard plaster, 
because that, too, coagulates the ferment which causes the 
formation of the valuable volatile oil. 

524. Ointments. Ointments are soft solids intended to be 
applied externally for the purpose of causing the absorption 
of certain medicinal agents through the skin, or to soften 
the skin or protect it, or as a soothing and healing appli- 
cation to denuded surfaces, etc. They are usually made of 
fatty substances, but they may also be prepared out of soft 
soap or of glycerite of starch or soft paraffins. 

The most common ointment bases are lard, the so-called 
simple ointment made out of lard and wax, lanolin or 
sheep's wool fat, petrolatum and glycerite of starch. 

Ointments may be divided into two classes, according to 
their medicinal application; namely, perfectly Hand oint- 
ments^ containing no active medicinal agent, and medicated 
ointments. 

The simple ointment of the pharmacopoeia is a mixture of 
four parts of lard and one part of yellow wax, melted 
together, and the melted mixture stirred until it congeals. 

When fats of low melting point are mixed with fats of 
high melting point, such as wax and spermaceti, the whole 
mixture must be stirred during the process of cooling to 
prevent the separation of the fat of higher fusing point. 
The stirring not only prevents that separation, but it also 
makes the ointment bulkier and softer and lighter in color. 
At the same time the process of stirring undoubtedly intro- 
duces air into the finished product, and the presence of air 
detracts from the keeping qualities of the preparation. 



SOLID PREPARATIONS NOT MADE BY EXTRACTION" 325 

Ointments made by fusion sometimes contain resins added 
to the fats, and liquid fixed oils are also employed in making 
certain ointments. 

The fusing point of a finished ointment is intended to be 
very nearly that of the temperature of the body. 

525. Medicated ointments are usually mixtures made out 
of the bland ointments with the finely powdered or semi-fluid 
medicinal agents. Solid extracts to be thoroughly incor- 
porated in ointments must first be rendered semi-fluid by 
trituration with water or diluted alcohol, after which they 
can be easily mixed with the fatty base or any other soft 
ointment base. 

Solid substances that cannot be reduced to a semi-fluid 
condition must be in the form of impalpable powder, which 
is first mixed with a small portion of the ointment base, the 
remainder of which is afterwards added gradually, and 
trituration is continued until the mixture is perfectly 
uniform. 

When an ointment is well made, a small amount of it 
spread very thinly on a piece of white paper with the spatula 
will show no lack of uniformity, no lumps or streaks. A 
good ointment feels perfectly smooth when rubbed between 
the fingers. 

One of the essentials in the preparation of good ointments 
is the employment of perfect materials. 

Lard and other fats are so liable to become rancid and 
irritating that only perfectly fresh lard or fat can be used. 
Eancid lard applied is much more likely to cause inflam- 
mation than to be soothing in its action. 

When soft soap is used in ointments, no fat is used with 
it, but sometimes it is necessary to add a little hot water to 
give the ointment the proper soft consistence. 

Glycerite of starch has the advantage of being water- 
soluble, so that an ointment made with that base is easily 



326 A CORRESPONDENCE COURSE IN PHARMACY 

washed off with tepid water and, moreover, glycerite of 
starch does not become rancid or change in any other 
unfavorable manner. / 

Petrolatum keeps a long time without alteration, but it is 
far less suitable for the preparation of ointments than animal 
fats, because petrolatum does not soften and penetrate the 
skin, but is suitable only for local dressings. 

When watery liquids are to be introduced into ointments, 
lanolin is very useful as an addition to the preparation, 
because very large quantities of water can be mixed with 
lanolin and the mixture is sufficiently firm; in fact, when 
water is added to lanolin, the mixture becomes more and 
more firm until as much water has been added as the 
lanolin can hold. Glycerin, also, when added to lanolin 
makes it stiffer instead of softer. 

526. Cerates are altogether like the ointments, with the 
exception that they have a higher melting point and are 
somewhat firmer. The simple cerate of the pharmacopoeia 
is a mixture of seven parts of lard and three parts of white 
wax, mixed together by fusion. Other cerates contain, in 
addition, resin. Cerates are used mainly as dressings. They 
may be medicated in the same manner as ointments. 

527. Plasters are still firmer external preparations, 
intended to be applied to circumscribed areas of the body. 
Plasters are made of metallic oleates, resins, gum-resins and 
wax. 

The most common simple plaster is called lead plaster, 
which consists of a mixture of oleate of lead and stearate of 
lead. This is made by boiling lead oxide and olive oil 
together, adding a small quantity of water. The water 
changes the lead oxide to lead hydroxide, which reacts with 
the oleate and stearate of glyceryl so that lead oleate and 
lead stearate are formed, together with glyceryl hydroxide 
or glycerin The glycerin is then washed out of the finished 



SOLID PREPARATIONS NOT MADE BY EXTRACTION 327 

plaster mass, and the latter is rolled into sticks ready for use 
in the preparation of medicated and adhesive plasters. 

Lead plaster is too hard and non-adhesive to be used 
alone. To render it adhesive, resins are added, the lead 
plaster and resin being melted together and the mix- 
ture stirred until cold. Wax is also added to adhesive 
plaster. 

When gum-resins are introduced into plasters, the best plan 
is to emulsionize the gum-resin by beating it up with diluted 
acetic acid until converted into a thick, uniform liquid, free 
from lumps. This liquid, strained, is then added to the 
melted plaster and the whole mixture kept warm and liquid, 
stirring it constantly until the diluted acetic acid has 
evaporated, so that the plaster becomes sufficiently firm on 
cooling. 

When soap is introduced into plasters, the soap is preferably 
mixed with hot water first, and the uniform soft soap mixture 
is then added to the plaster and the plaster-mass kept hot 
until the water added has been evaporated. 

•When solid extracts are added to plasters, the extracts 
must first be rendered semi-fluid by trituration with water or 
diluted alcohol, after which they can be added to the melted 
plaster, which is kept at a temperature barely sufficient to 
keep it fluid to permit of the requisite stirring. 

Plasters made by fusion are always stirred constantly 
during the process of cooling, until they become so firm that 
further stirring is impossible. This is to insure uniformity 
of composition. 

When volatile substances like camphor or menthol are 
introduced into plasters, the plaster is first melted and then 
allowed to cool until barely fluid before the volatile sub- 
stance is added, after which the mass is diligently stirred 
and cooled as rapidly as possible, to prevent the loss of any 
portion of the volatile medicament. 



328 A CORRESPONDENCE COURSE IN PHARMACY 

528. Suppositories are solid bodies with or without active 
medicinal ingredients, and they are intended to be intro- 
duced into cavities of the body for the purpose of local medi- 
cation. They are usually made of oil of theobroma, or cacao 
butter. This substance is peculiarly useful for this purpose, 
because it is a solid fat which does not soften gradually with 
an increase of temperature, but remains firm up to very 
nearly the temperature at which it suddenly liquefies. 

When suppositories are ordered to be made with oil of 
theobroma as the base, the operation is somewhat difficult, 
because the oil of theobroma liquefies so readily when 
handled, its melting point being about the temperature of 
the body. From the nature of the substance, it will be 
readily understood that it is likely to be either too hard or 
too soft to be easily formed into cones or globular bodies, 
such as constitute ■ the so-called suppositories. But no 
addition must be made to the oil of theobroma to lower its 
fusing point or increase it, because the superiority of oil of 
theobroma over all fatty bases that can be used for making 
suppositories depends upon its property of suddenly liquefy- 
ing at the right temperature. 

Suppositories are made to weigh from one to four grams 
or from fifteen to sixty grains, according to their uses. 

Bougies are long, slender pencils made out of materials 
similar to those employed in making suppositories, and are 
also employed for local medication of cavities and passages. 

Medicaments to be added to suppositories and bougies 
should, of course, be in a semi-fluid condition before they 
are incorporated with the base, or they should be in the 
form of impalpable powders. 

The mass for making suppositories may be mixed on a 
board with the spatula, or it may be made in a mortar with 
the pestle, or the oil of theobroma may be melted in a por- 
celain dish and the medicaments added to the melted base, 



SOLID PREPARATIONS NOT MADE BY EXTRACTION 329 

the mixture being stirred until it congeals, or stirred until 
barely fluid enough to be poured into suitable molds. 

529. Suppositories are formed either by hand or by mold- 
ing them in special molds. To make suppositories oy hand, 
the oil of theobroma may be cut into thin shavings with the 
spatula and the shavings worked with the spatula on the 
board until sufficiently soft and plastic and free from lumps, 
after which the medicaments can be easily incorporated, the 
mass scraped together, rolled out in a cylinder, and the 
cylinder cut into the requisite lengths, according to a scale 
prepared for the purpose. 

Rectal suppositories are usually about one inch in length 
and three-eighths of an inch in diameter at the base, while 
the apex is bluntly pointed, the shape being nearly conical. 
In fashioning suppositories in this manner, the mass should 
come in contact only with the board and spatula ; if the mass 
is touched with the fingers, it is apt to become smeary so 
that it cannot be formed at all. To prevent the mass from 
sticking to the board and spatula, a very small amount of 
lycopodium is dusted on the board, and the mass rolled on 
the dusted surfaced 

Molds are made in such a way at present that the mass can 
be pushed from a cylinder by, means of a piston into molds 
of any shape or size. These suppository machines can be 
used with a cold mass, and are the best because when the 
mass is not melted there can be no separation of the ingre- 
dients from one another. Molds intended to be used with a 
melted mass are much more difficult to manage. If the 
medicaments are not soluble in the melted oil of theobroma 
and especially if they are solid and heavy, they sink to the 
bottom of the melted oil and it is difficult even with constant 
stirring to keep the mixture uniform. Separation cannot be 
prevented when the stirring ceases and the mixture is poured 
into the molds. All that can be done is to stir the mixture 



330 A CORRESPONDENCE COURSE IN PHARMACY 

and allow it to cool off until barely fluid enough to be poured, 
and to have the molds so well chilled with ice that the 
mixture congeals rapidly when the molds have been filled. 
But there is another difficulty attending this operation. If 
the mold contracts at the low temperature more readily than 
the contents, and if the congealed mass does not contract in 
the same ratio, the suppository will be held so firmly in the 
mold that it cannot be removed, but will be broken in the 
attempt to extract it. 

Test Questions 

1. What is meant by a Galenical preparation ? 

2. By what methods are Galenical preparations made, as 
distinguished from the methods by which other preparations 
are made ? . • • 

3. What is the difference between an organic preparation 
and an inorganic preparation ? 

4. How would you mix one milligram of strychnine with 
one gram of sugar ? 

5. How would you mix one ounce of opium, one ounce of 
ipecac and eight ounces of milk sugar ? 

6. How would you mix five grains of a tough, moist 
extract with sixty grains of sugar ? 

7. How would you mix ten grains of a moist, tough 
extract with ten grains of sugar, the mixture to be divided 
into ten- powders ? 

8. How would you make a compound powder consisting 
of two chemical compounds ? What precautions are neces- 
sary to prevent any chemical changes of the ingredients ? 

9. How much morphine is contained in one and one-half 
grain of trituration of morphine ? 

10. What are the usual ingredients of medicinal con- 
fections ? 



SOLID PREPARATIONS NOT MADE BY EXTRACTION 331 

11. What ingredients are common to all kinds of troches ? 

12. What is an excipient ? 

13. If a pill-mass is to be made containing four medicinal 
ingredients, two of which are powders, one a tough, moist 
solid, and the third a volatile oil, how would you make the 
mass? 

14. What would you add to a solid extract of the con- 
sistence of thick honey to make a pill-mass of it ? 

15. What are the chief differences between acacia and 
tragacanth as excipients in pill-masses ? 

16. Which takes the longer time — to stiffen a pill-mass 
with powdered slippery elm or to stiffen it with starch ? 

17. What are the essential characteristics of a good pill- 
mass ? 

18. When is water used as an excipient in pill-masses ? 

19. W^hen is alcohol a better excipient than water ? 

20. Name two of the stickiest moist excipients. 

21. Name one of the best absorbent fibrous excipients and 
one of the best absorbent inorganic excipients. 

22. What is a granule ? 

23. What would you do when a prescription calls for pills 
and the ingredients prescribed for each pill weigh ten 
milligrams ? 

24. What is the proper way to make a flaxseed poultice ? 

25. What is the proper way to make a mustard plaster ? 

26. How would you make suppositories of oil of theobroma? 

27. What is simple ointment ? 

28. How does simple ointment differ from simple 
cerate ? 

29. How would you make an ointment of tar and tallow ? 

30. How would you make an ointment of cottonseed oil 
and hard paraffin ? 

31. What are the principal differences between lard and 
vaseline as ingredients of ointments ? 



332 A CORRESPONDENCE COURSE IN PHARMACY 

32. How would you make an ointment of resin, wax and 
lard ? 

33. How would you mix lard with a solid extract ? 

34. How would you test or examine an ointment to see 
whether or not it is well mixed ? 

35. What are the advantages of petrolatum over lard as 
an ointment base ? 

36. What are ointments used for and what are cerates 
used for ? 

37. What is lead plaster ? 

38. What is adhesive plaster ? 

39. How would you make a plaster of extract of henbane ? 

40. How would you mix adhesive plaster, camphor, olive 
oil and oil of lavender to make an ointment ? 

41. What are suppositories ? 

42. Why do the pharmacopoeias generally order oil of 
theobroma as the chief material out of which suppositories 
should be made ? 

43. How would you make suppositories of extract of 
stramonium ? 

44. How would you make suppositories of camphor ? 

45. How would you make suppositories containing lead 
iodide? * 



LESSON TWENTY-ONE 
XXXI 

Liquid Preparations Not Made by Processes of 
Extraction 

530. Water-solutions of inorganic chemical compounds are 
to be found in all pharmacopoeias. In the American 
pharmacopoeia they are called solutions, in English, and are 
given the title liquor in the Latinic nomenclature. 

The definition of the title liquor most frequently given in 
text-books is "a water-solution of a non-volatile substance," 
but mucilages, syrups, infusions and decoctions are also 
water-solutions of non-volatile substances. Among the 
"liquores" of our pharmacopoeia there are not now any prep- 
arations other than water-solutions of non-volatile inorganic 
chemical compounds, so that this group of preparations is 
at present well defined. 

Some of the official liquores are used only as materials out 
of which other preparations are made, but most of them are 
intended for medicinal use, external or internal. 

The waters or aquae of the pharmacopoeia are commonly 
defined as " water-solutions of volatile substances, "but while 
it is true that all of the preparations given the title "aqua" in 
the American pharmacopoeia are really water- solutions of 
volatile substances, it is equally true that there are other 
water-solutions of volatile substances not called by that title, 
as, for instance, several of the acids. 

531. A great majority of the aquse are water-solutions of 

333 



334 A CORRESPONDENCE COURSE IN PHARMACY 

volatile oils, and a scientific classification of the pharma- 
ceutical preparations would seem to require that the aromatic 
waters should be made to constitute a class by themselves 
and should not be grouped together with such solutions as 
ammonia water, chlorine water and solution of hydrogen 
dioxide, which are chemical preparations. 

The aromatic waters are nearly or quite saturated solutions 
of volatile oil, made by triturating the volatile oil with talcum 
or with calcium phosphate and then with water, after which 
the mixture is filtered, two cubic centimeters of volatile oil 
being generally used to prepare 1000 cubic centimeters of 
the finished product. 

But rose water and orange flower water are made by 
distillation, and bitter almond water is made by dissolving 
the volatile oil of bitter almond in the water without the 
aid of trituration with calcium phosphate. 

Chloroform water is prepared by adding enough chloroform 
to a convenient quantity of distilled water to maintain an 
excess of chloroform at the bottom of the bottle, so that 
when the contents are thoroughly shaken together, the excess 
of chloroform will sink to the bottom of the bottle and the 
saturated solution standing over the undissolved chloroform 
is poured off as required. 

The aromatic waters are employed chiefly as flavoring 
agents or as vehicles for more important substances. 

532. Mucilages are water-solutions of vegetable mucilage. 

The mucilage of acacia of the pharmacopoeia is made by 
dissolving 340 grams of acacia in small fragments in enough 
water to make the finished solution weigh 1000 grams. The 
acacia is first washed with cold water to remove dust, and 
then dissolved in the necessary amount of water to form the 
preparation, which must be kept in completely filled bottles 
in a cool place, in order to prevent fermentation. 

Mucilage of tragacanth is prepared by mixing G parts of 



LIQUID PREPARATIONS NOT MADE BY EXTRACTION 335 

tragacanth with a mixture of 18 parts of glycerin and 75 
parts of water, and letting the mixture stand twenty-four 
hours, stirring occasionally. The glycerin and water are 
first mixed and the mixture heated to boiling, after which 
the tragacanth is added. After twenty-four hours, the mix- 
ture is beaten until of uniform consistence and enough 
water is added to make the whole product weigh 100 grams, 
and the thick mucilage is forcibly strained through muslin. 
This mucilage, too, is likely to undergo fermentation and 
should therefore be prepared in quantities so small that they 
will be consumed in a short time. 

Mucilage of slippery elm bark is made by digesting bruised 
slippery elm in water over a water bath for one hour, after 
which the liquid is strained. Mucilage of sassafras pith is 
made by macerating sassafras pith with the prescribed quan- 
tity of water for three hours. 

All mucilages are liable to undergo fermentation and 
hence cannot be kept in stock more than a few days. 

533. Syrups are water-solutions of medicinal substances, 
sweetened with considerable quantities of sugar. 

The "syrupus," or simple syrup of the pharmacopoeia, is 
a water-solution of sugar made by dissolving 850 grams of 
coarsely powdered sugar in enough water to make the finished 
solution measure 1000 cubic centimeters. The sugar is 
either dissolved with the aid of heat and the solution raised 
to the boiling point, after which it is strained, or the sugar 
is dissolved by percolating water through it in an ordinary 
percolator. Simple syrup has a specific weight of about 
1.317, and is an almost saturated solution at ordinary 
temperatures, so that it crystallizes if placed in a cold room. 

Several of the medicated syrups of the pharmacopoeia 
contain inorganic chemical compounds, as, for instance, 
syrup of hydriodic acid, syrup of calcium lactophosphate 
and syrup of ferrous iodide. Other medicated syrups of the 



336 A CORRESPONDENCE COURSE IN PHARMACY 

pharmacopoeia contain organic medicinal substances, usually 
added in the form of fluid extracts. 

Several of the pharmacopceial syrups are used as flavoring 
ingredients or agreeable additions to mixtures. 

The presence of considerable quantities of inorganic 
chemical compounds in syrups tends to preserve them, so 
that such syrups may be made with a smaller quantity of 
sugar than is necessary to preserve syrups containing fer- 
mentable organic matter. 

534. Glycerites are solutions of pharmaceutical and 
medicinal substances in glycerin. Glycerin solutions are 
more permanent than water-solutions of the same substances. 
Medicated glycerites are few in number, and those contained 
in the pharmacopoeia are the glycerites of carbolic acid, 
tannic acid, boroglycerin and hydrastis. 

The glycerite of starch is a thick, translucent, jelly-like 
preparation made out of 1 part of starch, 1 part of water 
and 8 parts of glycerin, heated together at the temperature of 
from 140° to 144° 0. It is used mostly as an ointment base. 

The glycerite of yolk of egg, sometimes called glyconin, is 
a mixture of yolk of egg and glycerin, intended to be used 
in preparing emulsion-like mixtures, the yolk of egg acting 
as an emulsifying agent. 

535. Emulsions are liquid mixtures containing insoluble 
substances in a fine state of division, suspended uniformly 
throughout the whole liquid. The undissolved, finely 
divided substances may be volatile oils, fixed oils, oleoresins, 
resins, gum-resins or inorganic powders. 

Emulsions may be classified as follows: Seed emulsions, 
gum-resin emulsions, emulsions of fixed oils, emulsions of 
volatile oil and oleoresins, quasi-emulsions of inorganic 
powders. 

536. Emulsions of seeds are formed when the seeds are 
beaten and thoroughly triturated with water, because all 



LIQUID PREPARATIONS NOT MADE BY EXTRACTION 337 

seeds contain fixed oils, and they usually contain emulsin, 
which acts as an emulsifying agent. 

The only very common seed emulsion is the emulsion of 
almond, which is prepared as follows : Sweet almonds are 
blanched by first placing them in tepid water for a few 
minutes to loosen the seed-coat, which is then easily removed. 
The seed-coat of almonds can also be loosened by putting 
the almonds in cold water, but it takes much longer time. 
Boiling water should never be used, because it unfavora- 
bly affects the result, since the emulsin of the almond is 
coagulated by temperatures exceeding 60° 0. The blanched 
almonds are put in the emulsion mortar and beaten to a 
coarse powder. Sugar and acacia, previously mixed in the 
proportions ordered by the pharmacopoeia, are then added 
and mixed with the coarsely crushed almond. Enough 
water is then added and the whole mixture beaten into a 
smooth pulp or paste, free from lumps. More water is 
gradually added and the mixture triturated thoroughly until 
finally all the water to be used has been added, after which 
the emulsion is strained and is then finished. 

Sweet almond beaten up with water will form an emulsion 
without the addition of acacia and sugar, but such an 
emulsion of almond is thin and poor. The amount of fixed 
oil contained in the almond is so great and the emulsin in 
the almond is so insufficient as an emulsifying agent, that 
in order to get a rich emulsion it is necessary to add acacia, 
which is one of the most effective emulsifying agents we 
have. Sugar is added to sweeten the preparation. 

Emulsion of almond is used sometimes as a ' 'placebo," by 
which is meant a pharmaceutical preparation ordered by 
physicians in cases where no active medicinal agent is 
necessary, the ailment of the patient being one of imagina- 
tion. Emulsion of almond may also be used as a pleasant 
vehicle for medicinal substances of not too decided flavor. 



338 A CORRESPONDENCE COURSE IN PHARMACY 

A preparation called liydrocyanated emulsion is used in 
several countries of Northern Europe, and occasionally in 
other countries. This preparation when ordered by a 
physician is usually prescribed in heroic doses and in cases 
where life or death depends upon prompt administration of 
the preparation. Hence, hydrocyanated emulsion must be 
dispensed by the pharmacist with the least possible delay. 
It is a mixture of emulsion of sweet almonds with a certain 
quantity of amygdalin. In order to avoid unnecessary delay, 
the emulsion of sweet almond required for the preparation 
of hydrocyanated emulsion is made without first blanching 
the almonds. 

537. Gum-resin emulsions are formed when gum-resins are 
triturated with water. Two such emulsions are contained 
in the pharmacopoeia — emulsion of asafetida and emulsion 
of ammoniac. 

The gum-resin must be clean, and to that end should 
consist of selected pieces. These are crushed in the mortar, 
reduced to coarse powder and then beaten with a small 
amount of water until a perfectly smooth pasty pulp is 
obtained, free from lumps. More water is gradually added 
and the trituration continued until all of the water pre- 
scribed has been used. The mixture is then strained, and if 
the work has been well done there should be little if any 
residue left on the strainer. 

538. Emulsions of fixed oils, volatile oils and oleoresins are 
made with acacia, according to the so-called "Hager's rules." 

Hager's rule fixing the proportions of the materials 
required to make emulsions of fixed oils is as follows: Take 
4 parts of fixed oil, 2 parts of acacia in powder and 3 parts 
of water of emulsification. 

For emulsions of volatile oils and oleoresins, Hager's rule 
is: Take equal parts, by weight, of the volatile oil or 
oleoresin, powdered acacia and water of emulsification. 



LIQUID PREPARATIONS NOT MADE BY EXTRACTION 339 

The manipulations are as follows : Mix the oil thoroughly 
with the powdered acacia, then add the "water of emulsifi- 
cation" all at once, and immediately stir the mixture with 
the pestle in the mortar as rapidly as possible, until the 
mixture becomes as light colored as it can be made, thickens 
and crackles under the pestle, and the globules of oil or 
oleoresin entirely disappear. The emulsification is then 
finished. If any additional water is ordered to be added, it 
must be gradually added after the completion of the emul- 
sification, and finally the emulsion is thoroughly shaken in 
a bottle. 

Another method is to mix the powdered acacia and water 
first, which requires considerable dexterity and rapidity of 
motion, to avoid the formation of lumps. When a uniform 
mixture of the acacia and water has been made, the oil or 
oleoresin is then added, a little at a time, and the emulsifica- 
tion of each portion completed before another portion is 
added. 

A third method is to put the powdered acacia on the 
bottom of the mortar in the center, covering the acacia after- 
wards with the oil or oleoresin, and then adding the water 
of emulsification so carefully that the layer of oil covering 
the acacia is not disturbed, in order that the water may not 
come in contact with the acacia until the trituration begins. 
If the water should come in contact with the powdered 
acacia before brisk stirring begins, lumps would be formed, 
which it is afterwards extremely difficult to crush. Having 
now all the necessary ingredients in the mortar in the right 
proportions, the operator grasps the pestle and with an 
extremely rapid rotary motion in one direction accomplishes 
the emulsification, after which any additional quantity of 
water required may be gradually stirred in. 

The most common emulsions of fixed oils are made of cod- 
liver oil, castor oil, olive oil and oil of almond. The most 



340 A CORRESPONDENCE COURSE IN PHARMACY 

common emulsion of volatile oils is made of oil of turpentine. 
The only common emulsion of oleoresin is an emulsion of 
copaiba. 

Yolk of egg is also an effective emulsifying agent, employed 
in making emulsions of fixed oils and occasionally other 
emulsions. When the yolk of egg is used for this purpose, 
the oil is mixed with it before the water of emulsification is 
added. 

Powdered tragacantli can also be used, and is quite as 
effective as powdered acacia, but a much smaller amount of 
tragacanth will prove sufficient. The tragacanth, however, 
works slowly, so that it takes a longer time to finish the 
emulsion, which, however, when finished, holds together 
remarkably well. 

Irish moss jelly is also used as an emulsifying agent for 
fixed oils, but it is not so effective in reducing the oil to an 
extremely fine state of division, although the emulsion when 
finished is comparatively permanent. Unless the Irish moss 
used in preparing the jelly is carefully selected so that the 
jelly is nearly colorless, the emulsion made with this 
emulsifying agent is unsightly, whereas emulsions made with 
acacia or tragacanth have a much better and cleaner 
appearance. 

Another emulsifying agent sometimes used is tincture of 
soap bark, but tincture of soap bark contains an extremely 
active medicinal substance called saponin, and hence this 
emulsifying agent should never be used unless ordered by a 
physician, and no intelligent physician is ever likely to 
order it. The only reason why it has been employed is its 
wonderful emulsifying power and the ease with which the 
emulsification is effected by it. 

539. Chloroform and ether may be incorporated in 
mixtures with the aid of tragacanth. It is, in fact, a very 
easy task to make such mixtures. All that is necessary is 



LIQUID PREPARATIONS NOT MADE BY EXTRACTION 341 

to place the required quantity of powdered tragacanth in a 
dry, clean bottle, add the chloroform or ether, and shake 
the mixture so as to disintegrate any lumps of the powdered 
gum; then add the water required and shake the bottle 
vigorously, when a uniform emulsion will soon be 
formed. 

The emulsion of 'chloroform of the American pharmacopoeia 
contains oil of almond as well as chloroform. The best way 
to make it is to add the chloroform to the oil, then add the 
powdered tragacanth and finally the water of emulsification, 
stirring vigorously as in other emulsions and finally shaking 
the mixture. 

The chalh mixture of the pharmacopoeia is a quasi- 
emulsion obtained by triturating prepared chalk with 
acacia and sugar and then with water and cinnamon 
water. The insoluble prepared chalk is held in suspension 
in the mixture temporarily by the acacia, which dissolves 
in the water, but as the chalk is only temporarily sus- 
pended, the mixture must be shaken each time it is to be 
taken. 

Precipitated sulphur can also be held in suspension with 
the aid of acacia, and then triturated a sufficiently long 
time with the requisite amount of water. 

540. Spirits are defined as alcoholic solutions of volatile 
substances. They are mostly alcoholic solutions of volatile 
oils, which are very simple preparations. 

541. Liquid preparations for external use are generally 
simple solutions or mechanical mixtures. The ingredients 
are extremely varied. 

Therapeutically, the external liquid preparations are chiefly 
stimulants, rubefacients, lubricants, astringents and cooling 
or soothing applications. Antiseptic and disinfectant lotions 
are also very much used. 

Lotions may be water-solutions of inorganic or organic 



342 A CORRESPONDENCE COURSE IN PHARMACY 

substances, or they may even be alcoholic liquids. Lotions 
are for local use externally. Eye washes are technically 
known as colly via, while those used for nasal difficulties are 
called collunaria. 

Gargles are mostly water-solutions, but they, too, fre- 
quently contain alcoholic ingredients. Gargles, technically 
known as gargarismata, are used as washes for the 
throat. 

Injections are so miscellaneous in their character that it is 
impracticable to give any general description of them. They 
are aqueous, mucilaginous, oily or even alcoholic. They are 
injected by means of syringes into the body cavities through 
the rectum, ear or other openings. A rectal injection is 
called an enema. 

Liniments usually contain some fixed oil, volatile oil or 
soap, but may also be composed of other ingredients in 
liquid form, as, for instance, tinctures. Liniments are 
for external use, and are applied as washes or rubbed in by 
gentle friction. 

Collodions are solutions of so-called soluble guncotton or 
pyroxylin in a mixture of alcohol and ether. Simple col- 
lodion contains nothing else, but medicated collodions 
contain tannin, cantharidin and various other medicinal 
substances. When collodion is applied to the skin or to a 
wound, the alcohol and ether evaporate, leaving a continuous 
film of the pyroxylin. If the collodion is of suitable density, 
the film is sufficiently strong and elastic to form an effective 
covering. The lips of wounds may be held together by 
applications of collodion, but if the application is too thick, 
the contraction of the film may be painful. For this reason 
various additions to collodion are made to render the film 
elastic so that it may be less painful. The most common 
additions made for this purpose are glycerin, castor oil and 
Venice turpentine. 



LIQUID PREPARATIONS NOT MADE BY EXTRACTION 343 

Test Questions 

1. Mention several kinds of liquid preparations for 
external use. 

2. What is collodion made of and how is it made elastic ? 

3. What is the meaning of the title liquor in the Ameri- 
can pharmacopoeia ? 

4. What several kinds of water-solutions of non-volatile 
substances are common in pharmacy ? 

5. How are the aromatic waters made ? 

6. How is mucilage of acacia prepared ? 

7. How is mucilage of tragacanth prepared ? 

8. What proportions of sugar and water, by weight, are 
required to make just six pints of simple syrup ? 

9. How do you find these proportions most easily ? 

10. What quantity in cubic centimeters of mucilage of 
acacia can be made from 340 grams of acacia, assuming that 
the specific weight of the mucilage is 1.31 ? 

11. How much sugar is necessary in a medicated syrup ? 

12. How is glycerite of starch made ? 

13. What is an emulsion ? 

14. What substances will form emulsions when beaten 
with water without the addition of any other substance ? 

15. Describe how a good emulsion of almond is made. 

16. Describe how a good emulsion of ammoniac is made. 

17. What is Hager's rule for the production of fixed oil 
emulsions ? 

18. State Hager's rule for making emulsions of oleoresins. 

19. What is Hager's rule for the production of emulsions 
of volatile oils ? 

20. What are the principal emulsifying agents ? 

21. How would you make an emulsion containing one-half 
its volume of almond oil ? 

22. How would you make an emulsion containing oil of 
turpentine and olive oil together ? 



344 A CORRESPONDENCE COURSE IN PHARMACY 

23. How can an emulsion of ether be made ? 

24. Describe in detail how you would make an emulsion 
containing one-eighth of its volume of volatile oil of copaiba. 

25. What is the object of the acacia in chalk mixture ? 

26. What would you call an alcoholic solution of oil of 
peppermint ? 



LESSON TWENTY-TWO 

XXXII 

Extracts 

542. Infusions are ordered by the American pharmacopoeia 
to be made in accordance with the following general direc- 
tions, unless specially otherwise ordered: "An ordinary 
infusion, the strength of which is not directed by the 
physician nor specified by the pharmacopoeia, shall be pre- 
pared by the following formula: Take of the substance 
coarsely comminuted 50 grams, boiling wat<er 1000 cubic 
centimeters. Put the substance into a suitable vessel pro- 
vided with a cover. Pour upon it the boiling water. Cover 
the vessel tightly and let it stand for half an hour, then 
strain and pass enough water through the strainer to make 
the infusion measure 1000 cubic centimeters." These 
general directions are followed by a note reading as follows : 
"Caution, — The strength of infusions of energetic or power- 
ful substances should be specially prescribed by the 
physician. ' ' 

Special formulas are given in the pharmacopoeia for 
infusions of cinchona, digitalis and wild cherry and for 
compound infusion of senna, which preparations are not 
made in accordance with the general directions. 

The infusion of cinchona, U. S. P., 1890, was a percolate 
made with cold water, acidulated with aromatic sulphuric acid. 

The infusion of wild cherry is also a percolate and is made 
with cold water. 

345 



346 A CORRESPONDENCE COURSE IN PHARMACY 

The infusion of digitalis and the compound infusion of 
senna are made with boiling water. But other ingredients 
besides the drugs after which the infusions are named are 
added in these preparations, and the strength of each is not 5 
per cent, as ordered in the general formula. 

In other pharmacopoeias of the world, the infusions are 
generally made of 10 per cent strength. The American 
pharmacopoeia of 1880 ordered infusions of 10 per cent 
strength, but in the revision of 1890 the strength was 
changed to one-half of that. 

543. Decoctions are ordered by the American pharma- 
copoeia to be made as follows: "An ordinary decoction the 
strength of which is not directed by the physician nor 
specified by the pharmacopoeia shall be prepared by the 
following formula: Take of the substance coarsely com- 
minuted 50 grams, water a sufficient quantity. Put the 
substance into a suitable vessel provided with a cover, pour 
upon it 1000 cubic centimeters of cold water, cover it well 
and boil for fifteen minutes. Then let it cool to about 40° C. , 
express, strain the expressed liquid and pass enough cold 
water through the strainer to make the product measure 
1000 cubic centimeters." This general formula is followed 
by a note similar to that given under the head of infusions, 
namely: "Caution. — The strength of decoctions of ener- 
getic or powerful substances should be specially prescribed 
by the physician." 

According to the pharmacopoeia of 1880, decoctions were 
to be of 10 per cent strength, but the directions of 1890, as 
will be seen, changed the proportions so as to make these 
preparations only 5 per cent strength. 

Special formulas are given in the pharmacopoeia for decoc- 
tion of Iceland moss and compound decoction of sarsaparilla. 

The most common decoctions ordered by physicians are 
demulcent decoctions or thick, starchy decoctions. The 



EXTKACTS 347 

proportion of starchy matter required to make such a 
decoction must depend upon the percentage of starch in the 
substance out of which the decoction is made, and for that 
reason the proportions directed by the general formula of 
the pharmacopoeia are sometimes impracticable. 

In most of the pharmacopoeias of the world, the decoctions 
are ordered to be made of 10 per cent strength. 

544. Vinegars are liquid extracts made with diluted acetic 
acid as the menstruum. The Latinic title of a vinegar is 
"acetum." Many such preparations were used in olden 
times, but at present the American pharmacopoeia contains 
only two — the vinegar of opium and the vinegar of squill. 
Both of these are of 10 per cent strength, and they are both 
made by maceration. 

Diluted acetic acid is much stronger than ordinary table 
vinegar, for the diluted acetic acid of the pharmacopoeia 
contains 6 per cent of absolute hydrogen acetate, while table 
vinegar usually contains but 4J- per cent. Diluted acetic acid 
is an effective solvent for many of the active constituents of 
plant drugs, including alkaloids and many glucosides, espe- 
cially acrid substances; and diluted acetic acid is also capa- 
ble of dissolving small quantities of volatile oils and resins. 

Medicated vinegars are so disagreeable to the taste that 
they are seldom used. 

545. Tinctures are liquid extracts made with strong or 
diluted alcohol, but of less strength than the fluid extracts. 
A few of the preparations called tinctures in the pharma- 
copoeia are alcoholic solutions of resins or alcoholic solutions 
of inorganic substances. 

The common definition given of the title tincture is to the 
effect that it is "an alcoholic solution of non -volatile" matter, 
but, of course, the fluid extracts are just as much alcoholic 
solutions of non-volatile substances. If the title tinctura 
were restricted to alcoholic and hydro alcoholic liquid 



348 A CORRESPONDENCE COURSE IN PHARMACY 

extracts of plant drugs, our nomenclature would be in 
harmony with scientific classification. 

A great majority of the tinctures of the American 
pharmacopoeia are directed to be made by percolation, and 
the period of maceration between the packing of the drug in 
the percolator and the displacement of the solution is usually 
twenty-four hours, but in some cases the displacement of 
the solution formed is proceeded with immediately after 
packing or without preceding maceration. All tinctures 
that can possibly be made by percolation are in the American 
pharmacopoeia ordered to be so prepared ; in other pharma- 
copoeias of the world the tinctures are almost without excep- 
tion made by maceration without percolation. 

Tinctures of extract-like drugs, such as kino, and of 
resins, such as benzoin, guaiac and tolu, and of gum-resins, 
such as asafetida and myrrh, are, of course, not made by 
percolation, but are made either by simple solution, if the 
drug is completely soluble in the menstruum, or by macera- 
tion if only partially soluble, as in the case of gum-resins. 

When a tincture is made of any resin, coarse powder of 
the resin is used, and all that is necessary is to dissolve the 
resin in the alcohol. The tincture is finished as soon as the 
resin has been completely dissolved, and this does not usually 
require as much as seven days, the period prescribed in the 
pharmacopoeia. 

Tincture of iodine is a simple alcoholic solution of iodine. 

The tincture of ferric chloride is a mixture of solution of 
ferric chloride with alcohol, which is allowed to stand in a 
closely covered vessel for at least three months before it is 
used. The object to be attained by allowing the mixture to 
stand for at least three months is the formation of certain 
ethereal compounds by chemical reaction between the ferric 
chloride and the alcohol. 

Most of the tinctures in the pharmacopoeia are simple 



EXTRACTS 349 

tinctures, representing but one drug having the medicinal 
action expected of the preparation. Other tinctures repre- 
senting but one drug of value are flavored by additions of 
other substances, and finally there are tinctures called com- 
pound tinctures, containing more than one active ingredient. 

One class of tinctures to which the pharmacopoeia makes 
general reference is the class called " tinctures of fresh 
herbs." The pharmacopoeia gives the following general 
directions for making the tinctures of fresh herbs: "These 
tinctures, when not otherwise directed, are to be prepared 
by the following formula : Take of the fresh herb, bruised 
or crushed, 500 grams, alcohol 1000 cubic centimeters. 
Macerate the herb with the alcohol for thirteen days, then 
express the liquid and filter. ' ' Elsewhere in this book the 
statement has been made that some plant drugs are con- 
sidered to be more valuable in the fresh condition than after 
drying, but the plant drugs used in the fresh condition are 
not all herbs. Some of them are roots and rhizomes, and 
one fresh drug considerably used is a cactus. Tinctures of 
all kinds of fresh drugs are made in the same manner as the 
tinctures of fresh herbs. 

The tinctures of the pharmacopoeias of the world are not 
of uniform strength. One of the tinctures of the American 
pharmacopoeia, that of aconite, represents about 40 per cent 
of its weight of the drug. The tincture of veratrum viride 
represents about 50 per cent of its weight of the drug. The 
greater number of tinctures represent about 20 per cent; 
others 15 per cent, others 10 per cent, some only 5 per cent. 
The strength of each tincture is simply that established by 
custom, without any system. Doubtless some of the tinctures 
in use might with great advantage have been made stronger ; 
others might with equal advantage have been made less 
strong. The authorities having charge of the British 
pharmacopoeia announce that the guiding principle in 



350 A CORRESPONDENCE COURSE IN PHARMACY 

revising the formulas for tinctures in that book was a greater 
approach to uniform doses, but great changes in the strength 
of tinctures commonly employed, especially if the tinctures 
are made of poisonous drugs, are hazardous, and it has 
therefore been considered impracticable to change the 
strengths of tinctures in so radical a way as to bring about 
anything like uniform dosage. The two strongest tinctures 
in the American pharmacopoeia, those of aconite and vera- 
trum viride, are tinctures of extremely poisonous drugs, and 
the doses of those tinctures are accordingly extremely small. 
On the other hand, we have in the American pharmacopoeia 
tinctures of 10 per cent strength made out of a large number 
of drugs of comparatively small medicinal activity, so that 
their doses are extremely large. 

The tincture of ipecac and opium of the pharmacopoeia is 
made out of deodorized tincture of opium, fluid extract of 
ipecac and diluted alcohol. 

The tincture of nux vomica is made by dissolving the solid 
extract of nux vomica in alcohol and water. 

Ammoniatecl tinctures are tinctures prepared by maceration 
or percolation with aromatic spirit of ammonia as the 
menstruum. The ammoniated tinctures contained in the 
American pharmacopoeia are the ammoniated tincture of 
guaiac and that of valerian. 

Ethereal tinctures are tinctures made with ether as the 
menstruum. Such tinctures have been made of lobelia, 
valerian and other drugs. No ethereal tinctures are con- 
tained in our pharmacopoeia. 

546. Medicated wines are in some respects like the tinc- 
tures. They differ, in fact, from the tinctures only in that 
wine is the menstruum instead of alcohol or diluted alcohol. 
Wine to be used for the purpose of making the medicated 
wines must, according to the pharmacopoeia, be a white 
wine containing not less than 10 nor more than 14 per cent, 



EXTEACTS 351 

by weight, of absolute alcohol, but in the formulas presented 
by the pharmacopoeia this wine is usually strengthened by 
the addition of more alcohol. 

Any domestic wine having the characteristics described in 
the pharmacopoeia, such as California Eiesling, Ohio Ca- 
tawba, etc., may be used, but in all other countries either 
sherry or Malaga is used and ordered in the pharmacopoeias, 
and it is quite probable that American pharmacists very 
generally also use sherry. 

The wine of antimony of the pharmacopoeia consists of 
wine to which a solution of tartar emetic is added. Bitter 
wine of iron is wine with an addition of citrate of iron and 
quinine, flavored with tincture of sweet orange peel. . Wine 
of ferric citrate is wine with citrate of iron and ammonium 
added and also flavored with tincture of sweet orange peel. 
Wine of ipecac is a mixture of wine and fluid extract of ipecac. 
Other medicated wines are made by -maceration or percolation 
of the drug with the wine fortified with alcohol. 

547. Fluid extracts are liquid extracts of plant drugs, so 
prepared that each cubic centimeter of the preparation repre- 
sents the valuable constituents of one gram of the drug of 
which the preparation is made. Fluid extracts are extremely 
numerous in our country and very largely employed. They 
have not been extensively used in other countries, and in 
some foreign countries they are not used at all, while some 
recent foreign pharmacopoeias contain less than a dozen kinds. 

The uniform standard of strength of fluid extracts is 
simplicity itself. Every physician or pharmacist knows how 
much of the drug is represented by any quantity of the prep- 
aration without any effort of the memory, but the value of 
the uniform rule ends there, for the result of such a rule is 
that the dose of one fluid extract may be less than a drop, 
while the dose of another fluid extract may be more than five 
hundred times as great. 



ob'i A CORRESPONDENCE COURSE IN PHARMACY 

Some of the fluid extracts are very nearly saturated solu- 
tions of extractive matter; others again contain but very 
small quantities of extractive in solution. In other words, 
some fluid extracts are so strong that it would be imprac- 
ticable to make them any stronger, while others could easily 
be made several times as strong as they are. The rule which 
ought to govern in fixing the strength of any medicinal 
preparation would seem to be to make the preparation as 
useful and convenient as possible for the particular purposes 
for which it is to be employed, whether used internally or 
externally. [To make a whole class of medicinal prepara- 
tions as numerous as the class of fluid extracts in accordance 
with a mathematical rule would seem to be too much like 
making only one size of trousers for a whole army. If the 
trousers are too long for a short-legged soldier, the trouser 
legs may be cut shorter, but if they are too short, it would 
be inconvenient to cut off the soldier's legs to fit the trousers, 
and when medicinal preparations are arbitrarily made to 
conform to certain mathematical ratios similar difficulties 
are sure to arise. It is impossible to make all liquid extracts 
of such strength that the approximate adult dose for ordinary 
purposes of each and every such preparation shall be the 
same as that of every other preparation of the same class, 
but it is entirely practicable to divide the whole class into a 
few groups and to make the strength of each member of 
such a group such that the dose of all members of the same 
group will be approximately alike.] 

Fluid extracts are so difficult to prepare, owing to their con- 
centration, that pharmacists rarely undertake to prepare them. 
They are usually made only by manufacturing pharmacists. 

548. The colors of tinctures and fluid extracts vary con- 
siderably, but by far the greater number are of a dark red- 
brown or yellowish-brown color. Others are greenish -brown 
or red, green or yellow. 



EXTEACTS 353 

The amount of extractive matter contained in solution in 
a tincture or a fluid extract is easily found by evaporation of 
a definite quantity of the preparation. Some fluid extracts 
can contain but about 3 to 6 per cent of extractive matter, 
while others, again, may contain between 30 and 50 per cent. 
The tinctures, of course, contain smaller quantities, accord- 
ing to their percentage strength. 

549. Solid extracts are preparations of plant drugs made 
by separating the soluble matter from the drug by macera- 
tion or percolation with the most appropriate solvent, and 
the subsequent elimination of the solvent by distillation and 
evaporation. Most of the solid extracts of the American 
pharmacopoeia are ordered to be made of "pilular con- 
sistence," or a consistence suitable to the formation of the 
extract into pills without the addition of any excipient. As 
a matter of fact, however, the extracts enumerated in the 
pharmacopoeia and ordered to be made of pilular consistence 
are rarely found to be of that consistence; they are usually 
either softer or firmer. 

But some of the extracts of the pharmacopoeia are ordered 
to be entirely dry, and some of the extracts which are 
ordered to be made dry are also ordered to be reduced to 
powder for greater convenience. Doubtless all extracts 
that can without injury be made perfectly dry should also 
be powdered. 

A good and very familiar example of a hard, dry extract 
is the common black stick -licorice. The stick-licorice varies 
as to the amount of moisture it contains, some of it being 
sufficiently moist to render the stick more or less flexible, so 
that it can be bent more or less without breaking ; other 
sticks of black licorice are so hard and dry as not to be in 
any degree flexible. Some black licorice is so hard and dry 
that it can not only be crushed, but easily triturated to 
powder. When dissolved in water, it forms a sticky solu- 



354 A CORRESPONDENCE COURSE IN PHARMACY 

tion, the density of which depends upon the proportion of 
extract dissolved. Whenever the black licorice is at all 
wetted it at once becomes sticky. The color of extract of 
licorice, or stick-licorice, is a dark reddish-yellowish brown, 
much like the color of most of the solid extracts, and stick 
licorice is, in fact, in every respect a solid extract. 

The solid extracts differ in composition according to the 
drug from which they are made and according to the 
menstruum employed in making them. The method by 
which the extracts are generally prepared consists of two 
parts. The first part of the process is like that by which 
fluid extracts are made. It consists in the extraction of 
soluble matter by maceration or percolation. The second 
part of the process consists in the separation of the men- 
struum from the dissolved matter. 

Solid extracts are not of uniform strength with reference 
to the drug out of which they are made. Some extracts 
may be more than thirty times the strength of the drug, 
while others may be only twice the strength of the drug. 
That, of course, is determined by the total amount of soluble 
matter given up by the drug to the menstruum used, and 
also by the degree to which the extract is dried. 

The direction to evaporate an extract to a pilular con- 
sistence renders the strength of any one such extract more 
or less uncertain, because the expression "pilular consistence" 
may mean one thing to one operator and quite another thing 
to another. 

In cases where it is practicable to determine accurately the 
percentage of active constituents in the drug or the extract, 
the product can be made of absolutely uniform potency by 
dilution with the requisite quantity of sugar of milk or of 
glycerin. Dry and powdered extracts of uniform strength 
may be made by dilution with sugar of milk, and soft or 
semi-fluid extracts of definite strength may be made by 



EXTRACTS 355 

dilution with glycerin. Dry and powdered extracts are 
the most convenient for the preparation of compound pow- 
ders, troches, pills and certain other solid preparations; 
but soft or semi-fluid extracts are most convenient for the 
preparation of ointments, plasters, suppositories and liquid 
mixtures. 

The strength of a solid extract may be made to bear a 
simple relation to the drug it is made from, as follows : The 
total amount of extract produced may be made to exceed 
the natural yield of extractive and a sufficient amount of 
diluent added to bring about that result. The extracts of 
drugs yielding less than 10 per cent of extractive matter 
may be made to represent ten times their weight of the drug. 
Extracts from drugs yielding from 10 to 20 per cent of 
extractive can be made to represent, five times their weight 
of the drug, etc. Another plan for making the extracts as 
convenient and useful as possible would be to regulate the 
yield according to the dose so as to form a few classes of 
extracts, each member of one class having approximately the 
same dose. 

In all cases where it is practicable to determine the potency 
of a drug by assay, the extract made from the drug can be 
made of absolutely definite value in the same manner. Thus, 
in the American pharmacopoeia the extract of opium is a 
dry powder diluted with milk sugar, used in such proportion 
that the final product contains precisely 20 per cent of 
morphine, and the extract of nux vomica is a dry powder 
also diluted with milk sugar to obtain a product containing 
exactly 5 per cent of strychnine. Assayed extracts can 
also be prepared of a number of other alkaloidal drugs and 
of drugs containing resins. 

550. Oleoresins are ethereal extracts, and of these the 
American pharmacopoeia contains six. A typical example 
is the oleoresin of male fern. The aspidium or male fern is 



356 A CORRESPONDENCE COURSE IN PHARMACY 

put into a cylindrical glass percolator provided with a stop- 
cock and arranged with cover and receptacle suitable for 
volatile liquids. The drug is pressed down firmly and ether 
is slowly percolated through it, the ether being added in 
successive portions and the percolation continued until the 
drug is exhausted. The greater part of the ether is then 
recovered from the percolate by distillation over a water bath, 
the residue is transferred to a capsule or porcelain dish 
and the ether remaining is allowed to evaporate spontane- 
ously. The product remaining after all the ether has been 
evaporated constitutes the oleoresin. 

The oleoresins of the pharmacopoeia are semi-fluid. 

551. Precipitated resins are prepared from jalap, podophyl- 
lum and scammony. 

Resin of jalap is made from finely powdered jalap, which 
is percolated with undiluted alcohol until the drug is 
exhausted or until the end -percolate no longer produces more 
than a slight turbidity when dropped into water. The 
alcohol is then distilled off until the liquid is reduced to a 
certain degree of concentration and the concentrated liquid 
is poured into a large amount of water with constant stirring. 
The resin then precipitates. The precipitate is washed 
twice with water and is then collected on a strainer, allowed 
to drain, and then pressed, after which the resin is dried. 
The resin of podophyllum is made in a similar manner, but 
in this case 1 per cent of hydrochloric acid is added to the 
water employed to precipitate the resin and the water must 
be previously cooled to a temperature below 10° C, in order 
th t the precipitation may be made as complete as possible 
and to prevent the resin from forming lumps. Resin of 
scammony is made by digesting the powdered scammony with 
boiling alcohol, used in successive portions until no more 
alcohol-soluble matter remains in the marc. The alcohol is 
then distilled off until the remaining liquid has been reduced 



EXTRACTS 357 

to a syrupy consistence, and is then added to a large amount 
of water, after which the precipitated resin is washed and 
dried. 

Test Questions 

1. Name the aqueous liquid extracts mentioned in the 
pharmacopoeia. 

2. What are the differences between a decoction and an 
infusion of the same drug ? 

3. Under what circumstances are infusions and decoctions 
made of a different strength from that prescribed for 
"ordinary" infusions and decoctions? 

4. What is the pharmacopcsial strength of a medicated 
vinegar ? 

5. What is the percentage of acetic acid contained in a 
pharmacopoeial vinegar? 

6. What are the medicinal constituents usually contained 
in the medicated vinegars ? 

7. Define the title tincture. 

8. What is the difference between a tincture and a fluid 
extract of the same drug ? 

9. What menstruum is employed in the preparation of 
tinctures ? 

10. What is their percentage strength ? 

11. How are tinctures made ? 

12. Are all the tinctures liquid extracts ? If not, mention 
some tinctures that are not properly called extracts. 

13. In what respects do the tinctures and fluid extracts 
resemble each other ? 

14. How would you prepare a tincture of an undried or 
fresh root ? 

15. When it is stated that a tincture of veratrum viride is 
of 50 per cent strength, what does that statement really 
mean ? Does it mean that 100 grams of the preparation 



358 A 'CORRESPONDENCE COURSE IN PHARMACY 

reprosents all the activity of 50 grams of veratrurn viride ? 
If so, why ? If not, why not ? 

16. What tincture in the American pharmacopoeia is 
made out of a solid extract ? 

17. What is meant by a hydroalcoholic tincture ? 

18. What is an ethereal tincture ? 

19. What is the menstruum used in the making of an 
ammoniated tincture ? 

20. What is the percentage of alcohol contained in a 
medicated wine ? 

21. What name would you give to a liquid extract so pre- 
pared that one liter of it represents 200 grams of a plant 
drug? 

22. What is a fluid extract ? 

23. What quantity of solid matter is obtained from the 
evaporation of 100 cubic centimeters of a fluid extract? 

24. What is the standard of strength prescribed for solid 
extracts by the American pharmacopoeia ? 

25. How can the strength of a fluid extract, solid extract 
or tincture be made absolutely uniform ? 

26. What is the difference between an extract and an 
oleoresin ? 

27. What menstruum is employed for making oleoresins ? 

28. Why is glycerin prescribed to be mixed with some of 
the solid extracts ? 

29. For what purpose is sugar of milk added to some 
extracts ? 

30. Out of what kinds of drugs can oleoresins be made ? 

31. What is the consistence of a solid extract ? 

32. What is the consistence of oleoresins ? 

33. What is the consistence of precipitated resin ? 

34. What is the difference between an oleoresin soluble 
in diluted alcohol and one soluble only in ether ? 



LESSON TWENTY-THREE 

XXXIII 

Pharmacopoeias 

552. Pharmacopoeias are authoritative books containing 
the titles, definitions, descriptions and standards of purity 
and strength of commonly employed medicinal substances, 
together with directions for preparing simple and rational 
medicinal preparations such as physicians employ. 

Nearly every civilized nation has its own pharmacopoeia, 
and that pharmacopoeia has the authority of law. It is 
generally prepared by a governmental commission. 

The American Pharmacopoeia is, however, not prepared by 
the Government, but by a committee appointed by a delegate 
convention called the Pharmacopoeial Convention. This 
national convention for revising the pharmacopoeia meets 
decennially. The first convention met January 1, 1820, and 
the eighth decennial convention met May 1, 1900. The 
meetings of the convention are always held in the city of 
Washington. The membership of the convention is made 
up of not more than three delegates from each of the medical 
and pharmaceutical associations and colleges in the country, 
and the medical departments of the Army, the Navy and the 
Marine Hospital Service. This large convention elects a 
Committee of Revision of the pharmacopoeia, and that com- 
mittee does the work of revision. Instructions are given by 
the convention to its Committee of Eevision concerning the 
general features of the work and the principles to govern its 

359 



360 A CORRESPONDENCE COURSE IN PHARMACY 

scope. They may instruct the committee concerning the 
language of the text, the system of weights and measures to 
be employed, the extent to which definite standards of 
strength may be fixed for plant drugs and their preparations, 
etc., but all details are of necessity entrusted to the Revision 
Committee. The Committee of Revision appointed by the 
decennial convention of 1880 and those appointed by the 
conventions of 1890 and 1900 all consisted of twenty-five 
members, about half of them physicians and the remainder 
pharmacists. 

The work of revising the pharmacopoeia usually occupies 
from two to four years, and when that work is completed, 
the officers of the convention make arrangements for its 
publication. 

553. The medicinal substances included in the pharma- 
copoeia are those which in the judgment of the members of 
the Committee of Revision are of sufficient importance and 
sufficiently commonly employed to require that their identity, 
quality, purity and strength shall be regulated. But it may 
be said in a general way that simple drugs and substances of 
definite chemical composition are those entitled to a place 
in any pharmacopoeia, and that complex mixtures are 
generally excluded. The fact that a certain preparation is 
extensively used does not entitle it to a place in the pharma- 
copoeia, unless it is a rational preparation such as educated 
men licensed to practice medicine may consider useful. 
Nearly all pharmacopoeias still retain a small number of 
mixed nostrums which gained admission to the pharma- 
copoeias a long time ago, when the scientific principles along 
which pharmacopceial revision should proceed had not yet 
taken form. [One of the pharmacopoeias, for instance, still 
retains a preparation containing over fifty different ingredi- 
ents, the sole reason for its retension in that pharmacopoeia 
being that the preparation is still occasionally called for at 



PHARMACOPOEIAS 361 

the drug stores by ignorant people. The presence of such 
compounds in any pharmacopoeia seriously detracts from its 
dignity and character, and it is evident that any preparation 
for which there is a demand may be made and sold whether 
it is contained in the pharmacopoeia or not. In the Ameri- 
can Pharmacopoeia there are forty or fifty preparations of a 
complex character or of doubtful utility that should be 
transferred to the National Formulary as unworthy of a place 
in the National Pharmacopoeia. These preparations include 
Lady Webster's dinner pills, Plummer's pills, Morrison's 
pills, paregoric, compound cathartic pills, Griffith's mixture, 
etc., all of which preparations disfigure the pages of any 
scientific pharmacopoeia. ] 

554. As to the plant drugs contained in the pharmacopoeia, 
the Revision Committee is largely guided by what is known 
concerning the constituents found in them by chemical 
investigation. Any drug containing an alkaloid is necessarily 
a potent medicinal agent and might well be included in the 
pharmacopoeia, even if it is comparatively little used, whereas 
a plant known not to contain appreciable quantities of any 
of the classes of plant constituents to which medicinal value 
may be attributed should be excluded from the pharma- 
copoeia, unless other evidence of its utility is conclusive. 

Whenever any plant drug is introduced into the pharma- 
copoeia, provision should also be made for suitable prepara- 
tions of it, for physicians do not order crude plant drugs to 
be taken in substance. Such preparations as fluidextracts, 
tinctures, extracts and other rational pharmaceutical con- 
centrations or solutions are, therefore, introduced into the 
pharmacopoeia as the character of each drug may require. 
This rule has not been strictly observed in the past, for we 
find in the pharmacopoeia of 1890 such drugs, for instance, 
as wormwood and pokeberries, without any preparations of 
these drugs. 



3G2 A CORRESPONDENCE COURSE IN" PHARMACY 

Iii past generations it was held that the pharmacopoeia 
should not recognize any new medicinal agent, but that the 
utility of a medicinal substance should be thoroughly demon- 
strated by many years of experience and observation before 
it could be consistently included among the official medicines. 
It was also held that any medicinal substance already intro- 
duced in the pharmacopoeia ought not to be dropped unless 
its use had been discontinued. However, more rational ideas 
prevail at present. 

555. Any substance of definite chemical composition may 
be rationally introduced into the pharmacopoeia as soon as it 
is evident that it possesses physiological and medicinal effects 
indicating that it deserves to be tried in the practice of 
medicine. 

556. It is no longer held that the presence of any given 
medicinal substance in the pharmacopoeia constitutes evidence 
of its value, nor is it held that the absence of any medicinal 
substance from the pharmacopoeia indicates that it does not 
deserve to be used, for it is now recognized that the func- 
tions of the pharmacopoeia are not to recommend or condemn 
medicinal agents, but simply to provide means by which 
their identity, purity and strength may be fixed, so that 
physicians may attain reasonably uniform results from their 
use. 

557. If there were no pharmacopoeia or other means of 
establishing uniformity in medicinal agents, safe and scien- 
tific medication would be impossible. The tincture of digi- 
talis dispensed in one drug store should be of precisely the 
same potency as in another. In the pharmacopoeia of 1870 
it was provided that opium in powder should contain not less 
than 10 per cent of morphine, but nothing was said, about 
the maximum amount of morphine which powdered opium 
may contain without rendering it unsafe. Some samples of 
powdered opium contain about 20 per cent of morphine. 



PHAKMACOPGEIAS 363 

Hence under that pharmacopoeia it was possible for one 
pharmacist to dispense a powdered opium twice as strong as 
that dispensed by another pharmacist. Clearly, that phar- 
macopoeia failed in establishing a proper standard of strength 
for that drug. In 1880 the pharmacopoeia ordered that 
powdered opium should contain not less than 12 per cent 
nor more than 16 per cent of morphine, and it was, there- 
fore, possible while that pharmacopoeia was in force to obtain 
powdered opium in one drug store that was one-third stronger 
than the powdered opium dispensed in another drug store. 
In 1890 the Eevision Committee introduced in the pharma- 
copoeia our present standard of morphine strength for 
powdered opium, which provides that the drug shall contain 
not less than 13 nor more than 15 per cent, but clearly the 
most proper standardization of powdered opium would be 
one requiring an absolutely fixed percentage of morphine, 
above or below which no deviation should be permitted, since 
it is as easy to enforce such a rigid and uniform standard as 
it is to enforce variable standards, for, in order to fix 
the morphine strength of opium in any manner, the opium 
must first be assayed, after which poorer and richer opiums 
are mixed until the average complies with the pharmacopoeial 
requirements. Then the product can quite easily be made 
to have an absolutely fixed morphine strength. The Phar- 
macopoeia of 1900 makes the strength of opium from 12 to 
12^ per cent of morphine. 

558. With reference to tests for purity, absolute freedom 
from all impurities is not insisted upon, unless necessary, 
because small amounts of other substances may be present 
in medicinal agents without impairing their medicinal value, 
and in such cases the purity tests are so framed as to insure 
satisfactory results without imposing hypercritical standards 
which cannot be attained without great difficulty. 

559. The essential distinctive features of the text of the 



364 A CORRESPONDENCE COURSE IN PHARMACY 

pharmacopoeia are as follows : The titles, the definitions of 
the titles, the descriptions, the identity tests, the purity 
tests, the potency tests or quantitative tests, the working 
formulas, the directions for the preservation of the medicinal 
substances, the general directions, and the tables. 

560. The titles of the medicinal substances in the pharma- 
copoeia are of two kinds — the Latinic title and the technical 
English title. The Latinic title is not Latin, except in a 
minority of cases ; it is simply Latinic in form. The reason 
for retaining at this day in the pharmacopoeia Latinic titles 
for the medicinal substances is the ease with which scientific 
technical titles can be constructed having a Latinic form, and 
the great difficulty which is encountered in the effort to 
construct scientific technical titles of any other kind. The 
Latinic titles are in most cases arbitrarily coined words, and 
their meaning is specific and fixed. 

In many pharmacopoeias the Latinic titles of plant drugs 
are their only technical titles, for the other titles of the plant 
drugs are merely the popular names current among the 
people. A great change has been made in the American 
Pharmacopoeia in this respect. Our pharmacopoeia formerly 
employed such titles as "deadly nightshade," "dandelion," 
"foxglove" and "German chamomile." It now substitutes 
for those names the technical titles belladonna, taraxacum, 
digitalis and matricaria. Much remains to be done, how- 
ever, to complete this commendable reform. There seems to 
be no good reason why in pharmacy and medicine we should 
not substitute the technical titles myristica for nutmeg, 
viburnum prunifolium for black haw (just as we have sub- 
stituted viburnum opulus for cramp bark), ulmus for elm, 
galla for nutgall, coccus for cochineal, allium for garlic, etc. 

The technical titles of plant drugs are usually the genus 
names of the plants from which the drugs are derived. In 
some cases they are old genus names now discarded by 



PHAKMACOPCEIAS 365 

botanists, and in other cases they are species names now or 
formerly in use. The title of rhubarb is rheum, which is 
the botanical genus name of the plant yielding the root 
called rhubarb. The Latinic title of sweet flag is calamus, 
which is the species name of the plant acorus calamus, which 
yields the drug. 

But in some cases the Latinic titles have no connection 
with the botanical names; they are arbitrarily adopted and 
purely pharmaceutical titles. The word bucliu is used as 
a Latinic title and also as the English technical title for 
one of our much used drugs, but buchu is the name employed 
by the Hottentots to designate the drug. Tragacantha is 
the Latinic title of the gum which in English we call traga- 
canth, but the word tragacantha is not a botanical title. 

In some pharmacopoeias the Latinic titles of the plant 
drugs are generally made up of two words, one indicating 
the botanical source of the drug and the other the plant- 
organ or plant-part employed. For instance, the title of 
rhubarb is in such a pharmacopoeia rhei radix, which trans- 
lated into English means the root of rheum, whereas in the 
American Pharmacopoeia rhubarb is given the Latinic title 
rheum, which is considered sufficient, because the root is the 
only part of rheum that is medicinally employed. But when 
two different organs of the same plant are separately employed 
as drugs it is, of course, necessary that the pharmacopoeia 
should distinguish between them in the titles. Thus, our 
pharmacopoeia gives belladonna root the title belladonna 
radix and belladonna leaves the title belladonna? folia. 

In cases where two or more different species of the same 
plant genus furnish drugs, the genus name is, of course, 
insufficient to designate each drug. In such cases, the species 
name is used together with the genus name. The Latinic 
title of peppermint is therefore mentha piperita, and the title 
of spearmint mentha viridis. 



3G6 A CORRESPONDENCE COURSE IN PHARMACY 

In naming Indian cannabis, which consists of the flowering 
tops of cannabis sativa grown in the East Indies, it is neces- 
sary to call it Cannabis Indica, because cannabis sativa grown 
in other countries does not constitute the drug. 

Sometimes the botanical titles of plants yielding drugs are 
modified in their endings to "transform them into specific 
titles for the drugs. The botanical title of the almond tree 
is primus amygdalus, but the seed or almond is called 
amygdala. In the British Pharmacopoeia the title for cloves 
is caryopliyllum, derived from the old botanical name 
"caryophyllus. " 

The titles of pharmaceutical preparations are generally 
made up of two words, one indicating the character of the 
preparation and the other giving the name of the drug of 
which the preparation is made. Tincture of rhubarb is, for 
instance, called tinctura rliei, and the extract of rhubarb, 
extractum rhei. [The next chapter of this book will be 
devoted to Pharmaceutical Nomenclature.] After giving 
the Latinic title and then the English technical title, the 
pharmacopoeia next names in brackets any very common or 
recently used English name or names. In speaking of gum 
arabic, the pharmacopoeia, for instance, puts the text as 
follows : 

ACAOIA 

Acacia 

[Gum Arabic] 

In this case it will be seen that the Latinic title and the 
English title are identical, as is the case with very many of 
the drugs of the pharmacopoeia. 

561. After the titles and common names of crude drugs 
and chemicals, we find next the definition of the title. 

The definitions of plant drugs are very brief. They state 
what part of the plant constitutes the drug, the name of the 



PHARMACOPOEIAS 367 

plant itself, and the botanical family to which it belongs. 
The definition of the title althcea is : "The dried root of Altlma 
officinalis , Linne (Fam. Malvaceae)." Aloe Socotrina is 
defined as, "The inspissated juice of the leaves of Aloe Perryi, 
Baker, Aloe vera (Linne), Webb, Aloe Chinensis, Baker, or 
other species of Aloe (Fam. Liliacem)." The definition of 
Cambogia^is, "A gum-resin obtained from Garcinia Han- 
burii, Hooker filius (Fam. Guttiferw)." The definition of 
Eucalyptus is, "The leaves of Eucalyptus globulus, Labil- 
lardiere (Fam. Myrtacea), collected from the older parts of 
the tree. " That of Frangula is, "The dried bark of Rhamnus 
Frangula, Linne (Fam. JZhamnaceai), collected at least one 
year before being used." 

The definitions of chemical compounds are their molecular 
formulas, but these are sometimes supplemented by additional 
notes when the molecular formulas are not sufficiently 
definitive. Under the title of Hyoscyamine Hydrobromate, 
the molecular formula is given, but as hyoscyamine and 
atropine have the same molecular formula, it is necessary to 
add the statement that hyoscyamine hydrobromate is the 
hydrobromate of an alkaloid obtained from hyoscyamus. 

Definitions are not given of the titles of pharmaceutical 
preparations, because the title itself and the directions given 
for making the preparation render a definition unnecessary. 

562. After the definitions, the pharmacopoeia gives neces- 
sary technical descriptions. These descriptions are framed 
in accordance with a general plan. They begin with the 
description of the most striking external features of the 
substances named, such as size, shape and color, afterwards 
mentioning such features and properties as require closer 
examination, as, for instance, the internal structure, odor 
and taste, solubility in common solvents, and specific weight, 
etc. Whenever practicable and useful, the pharmacopoeia 
also calls attention to certain common signs of inferiority, 



3G8 A CORRESPONDENCE COURSE IN PHARMACY 

and directs that drugs possessing certain stated evidences of 
unfitness shall not be used. 

The following description of colchicum seed will serve to 
illustrate the general style : 

"Subglobular, about 2 mm. in diameter, very slightly 
pointed at the hilum; externally reddish-brown, finely pitted; 
internally whitish; tough and of almost bony hardness; 
nearly inodorous; taste bitter and somewhat acrid." 

The student will see that the descriptions are amplifications 
of definitions and are necessary to the intelligent selection 
of good drugs. When the pharmacopoeia directs that leaves 
of the second year's growth constitute the drug, the first 
year's leaves must, of course, not be used. When the drug 
is to consist of the inner bark, the outer bark must be 
separated from it, and the inner bark must not be accompanied 
by any of the wood. When root-bark is ordered, stem-bark 
should not accompany it, nor should the whole root be used. 
Flowering tops should not be made to include the whole 
plant, and when the drug is defined and described as consist- 
ing of leaves, stems and stalks must be removed. Eoots 
and rhizomes must be free from adhering dirt, etc. 

A drug which has the fresh, natural color belonging to it 
when well cured and preserved, and which possesses in a high 
degree and unaltered the peculiar odor and taste which 
characterize it, will generally be found of satisfactory 
medicinal quality; but a drug which is discolored or the 
odor or taste of which is impaired cannot be of good quality. 

Some of the drugs imported from distant parts of the 
world are found to require thorough garbling before they are 
fit for use. By garbling is meant the removal from a drug 
of admixtures, impurities, decayed portions, and other things 
that do not belong to it, under the pharmacopoeial definitions 
and descriptions. Occasionally these admixtures and im- 
purities amount to a considerable proportion; 20 per cent of 



PHAKMACOPCEIAS 369 

sand is not uncommon in asafetida, and more than 20 per 
cent of stems and stalks, legumes and other admixtures in 
Alexandrian senna. 

The following description of morphine sulphate will serve 
as an example of descriptions of organic chemical com- 
pounds: 

"White, feathery, acicular crystals of a silky luster; odor- 
less and having a bitter taste ; permanent in the air. 

"Soluble at 15° C. in 21 parts of water and in 702 parts 
of alcohol, in 0.75 part of boiling water, and in 144 parts of 
boiling alcohol ; almost insoluble in ether. 

"When heated for some time at 100° 0., the salt loses 
three molecules (7.12 per cent) of water of crystallization; 
the remaining two molecules (4.75 per cent) are gradually 
expelled by raising the temperature to 130° C. At 255° 0. 
the salt melts and upon ignition it is consumed, leaving no 
residue. 

"The salt is neutral to litmus paper." 

In reading this description, the student will observe how 
the various properties and behavior of the compound are 
mentioned in the order in which they may be most readily 
determined. To find the solubilities of substances, practical 
trials would be necessary, if the solubilities are to be employed 
as means of identification. The effects of various degrees 
of temperature must, of course, also be determined experi- 
mentally, and the reaction of a substance upon test paper 
ascertained by actual trial. But the color, form, odor and 
taste are more readily ascertained and are therefore mentioned 
first. 

Descriptions of inorganic chemical compounds are exempli- 
fied by that given under the title potassium iodide : 

"Colorless, transparent or translucent cubical crystals (the 
white, opaque commercial variety being crystallized from an 
alkaline solution and less pure), or a white granular powder 



370 A CORRESPONDENCE COURSE IN PHARMACY 

having a peculiar, faint, iodine-like odor and a pungent, 
saline, afterwards bitter taste ; permanent in dry air and but 
slightly deliquescent in moist air. 

''Soluble at 15° C. in 0.75 part of water, and in 18 parts 
of alcohol, in 0.5 part of boiling water and in 6 parts of boil- 
ing alcohol; also soluble in 2.5 parts of glycerin. 

"When heated the salt decrepitates. At a low red heat it 
fuses and at a bright red heat it is volatilized without 
decomposition. 

"Its aqueous solution is neutral, or has at most a scarcely 
perceptible alkaline reaction upon litmus paper." 

Descriptions of pharmaceutical preparations are rarely 
given in the American Pharmacopoeia, but are not uncommon 
in other pharmacopoeias. It may be assumed that when a 
pharmaceutical preparation is made out of proper materials 
which correspond to the descriptions given in the pharma- 
copoeia and the directions are carefully carried out,, the prod- 
uct will be uniformly of satisfactory character. But if the 
operator who makes the preparation uses improper materials 
or does not exercise sufficient care and skill, the product may 
be an unfit one, and it may be practicable to detect the 
unfit character of a pharmaceutical preparation even by its 
physical properties. Descriptions of pharmaceutical prep- 
arations therefore have practical value. An unfit tincture 
or fluidextract or oleoresin may, for instance, exhibit a color 
which deviates so far from the proper color of a good prod- 
uct that it may be immediately rejected solely on that 
sufficient evidence of unfitness. To illustrate, we may 
mention that tincture of Cannabis Indica made from a good 
drug and in the manner described in the pharmacopoeia has 
a vividly green color, and if the pharmacopoeia should 
mention that color, any tincture of Cannabis Indica not hav- 
ingthat color would at once be recognized as not in accord- 
ance with the pharmacopoeial requirements. 



PHARMACOPOEIAS 371 

563. After the descriptions, the pharmacopoeial text gives 
a series of tests called identity tests. These are applicable 
to chemicals. One of the tests by which sodium sulphite 
may be identified is that "when strongly heated, the com- 
pound emits vapors of sulphur and of sulphur dioxide and 
leaves a residue of sodium sulphate," although these facts 
alone are not sufficient for its identification. An additional 
identity' test for sodium bisulphite is as follows: "On the 
addition of hydrochloric or sulphuric acid, the aqueous solu- 
tion of the salt evolves sulphur dioxide, which is recognized 
by its odor and by its blackening a strip of paper dipped in 
mercurous nitrate test solution and held over the escaping 
gas." The description and identity tests applicable to ferric 
chloride are as follows : 

"Orange-yellow, crystalline pieces; odorless or having a 
faint odor of hydrochloric acid and a strongly styptic taste; 
very deliquescent in moist air. 

"Freely and completely soluble in water and in alcohol; 
also in a mixture of 1 part of ether and 3 parts of alcohol. 

"At 35.5° C. the salt melts, forming a reddish-brown 
liquid. When strongly heated, it decomposes with the loss 
of water and hydrochloric acid, while the inodorous salt sub- 
limes, leaving a residue of ferric oxide., 

"The dilute aqueous solution of the salt is acid to litmus 
paper and yields a brownish-red precipitate with ammonia 
water, a blue one with potassium ferricyanide and, with silver 
nitrate, a white one insoluble in nitric acid." 

564. Following the identity tests, the pharmacopoeia next 
gives tests for purity. Under the head of ferric chloride, 
the purity tests are as follows : 

"If the iron be completely precipitated from a solution of 
the salt by an excess of ammonia water, the filtrate should 
be colorless and should not yield either a white or a dark 
colored precipitate with hydrogen sulphide (absence of zinc 



372 A CORRESPONDENCE COURSE IN PHARMACY 

or copper) ; nor should it leave a fixed residue on evaporation 
and gentle ignition (absence of salts of the fixed alkalies). 

"On adding a clear crystal of ferrous sulphate to a cooled 
mixture of equal volumes of concentrated sulphuric acid and 
a moderately dilute solution of the salt, the crystal should 
not become colored brown nor should there be a brownish- 
black color developed around it (absence of nitric acid). 

"If to a dilute solution of the salt a few drops of freshly 
prepared potassium ferricyanide solution be added, a pure 
brown color should be produced, without a tinge of green or 
greenish-blue (absence of ferrous salt). 

"A 1 per cent aqueous solution of the salt when boiled in 
a test tube should remain clear (absence of oxy chloride)." 

565. The student will observe that the impurities which 
the tests are intended to disclose are indicated in parenthesis 
after each test. The impurities for which tests are prescribed 
are, of course, those which might naturally be expected to 
be found present in view of the materials employed in making 
the medicinal preparation and the manner in which those 
materials are used. When certain small amounts of impuri- 
ties are tolerated, the tests prescribed establish the limits of 
toleration. This is illustrated by the following tests under 
the head of sodium carbonate : 

"If 5 cc. of the aqueous solution be slightly supersaturated 
with acetic acid, the addition of 0.5 cc. of sodium cobaltic 
nitrite should not render it turbid within one hour (limit of 
potassium). 

"If 1.2 gm. of the salt be dissolved in 10 cc. of diluted 
nitric acid, then 0.5 cc. of decinormal silver nitrate solution 
added and the precipitate, if any, removed by filtration, the 
clear filtrate should remain unaffected by the further addition 
of silver nitrate solution (limit of chloride). 

"If 2.5 gm. of the salt be dissolved in 10 cc. of diluted 
hydrochloric acid and 0.1 cc. of nitric acid and 0.1 cc. of 



PHARMACOPEIAS 373 

barium chloride solution added and the precipitate, if any, 
removed by nitration, the clear nitrate should remain unaf- 
fected by the further addition of barium chloride solution 
(limit of sulphate, sulphite and hyposulphite)." 

566. After the purity tests, we find the quantitative tests. 
Under sodium carbonate the quantitative test is as follows : 
"To neutralize 1 gm. of inodorous sodium carbonate 
(deprived of its water of crystallization by heat immediately 
before being weighed) should require not less than 18.7 cc. 
of normal sulphuric acid (corresponding to not less than 98.9 
per cent of the pure salt)." 

Under the head of diluted hydrocyanic acid, the pharma- 
copoeia states: 

"To ascertain the percentage strength, mix in a flask of 
the capacity of about 100 cc. 0.27 gm. of hydrocyanic acid 
(obtained by the official process of preparation), with sufficient 
water and magnesia to make an opaque mixture of about 
10 cc. Add to this two or three drops of potassium chromate 
solution and then from a burette decinormal silver nitrate 
solution until a red tint is produced, which does not again 
disappear by shaking. Each cc. of silver nitrate solution 
used indicates 1 per cent of absolute hydrocyanic acid. 

"After ascertaining the strength of the distillate, dilute it 
with distilled water so as to bring it to the strength of 2 per 
cent of absolute acid. Lastly, test the finished product 
again, when 1.35 gm. of it should require for complete pre- 
cipitation 10 cc. of decinormal silver nitrate solution." 

In this case it is, of course, intended that any diluted 
hydrocyanic acid, in order to be fit for medicinal use, should 
be of exactly 2 per cent strength, and that consequently 1.35 
gm. of it should require, for complete precipitation no 
more and no less than 10 cc. of decinormal silver nitrate 
solution. The importance of this test will be appreciated 
from the fact that the pharmacist who dispenses the diluted 



374 A CORRESPONDENCE COURSE IN PHARMACY 

hydrocyanic acid is responsible for its strength, no matter by 
whom the preparation may have been made, and that a 
diluted hydrocyanic acid materially deficient in strength, as 
well as a diluted hydrocyanic acid much too strong, may 
cause the loss of human life. 

The solution of potassium arsenite of the pharmacopoeia 
is a pharmaceutical preparation for which purity tests are 
unnecessary and impracticable, but for which a quantitative 
test is prescribed as follows: "If 24.7 cc. of the solution be 
boiled for a few minutes with 2 gm. of sodium bicarbonate 
and the liquor when cold diluted with water to 100 cc. and 
mixed with a little starch solution, it should require from 
49.4 to 50 cc. of decinormal iodine solution to produce the 
blue tint of iodide of starch (corresponding to 1 gm. of 
arsenous acid in 100 cc. of the solution)." 

567. The student will appreciate the fact that these several 
kinds of tests prescribed by the pharmacopoeia must be intel- 
ligently applied; that pharmacists are responsible for the 
identity, purity and strength of the preparations they dis- 
pense, and that accordingly sufficient scientific training is a 
necessary preliminary to the practice of pharmacy. All the 
apparatus, reagents and other facilities necessary to the 
proper application of the pharmacopoeial tests must be found 
in every properly equipped pharmacy, and a disregard of the 
pharmacopoeial requirements in these particulars is treated 
as a violation of law, punishable according to the gravity of 
the case. No pharmacopoeia in the world is more precise 
and careful in establishing just and proper tests of identity, 
purity and strength of medicinal substances than the Ameri- 
can Pharmacopoeia, but in no other country are the require- 
ments of the pharmacopoeia less generally respected. This 
neglect cannot continue much longer without jeopardizing 
the very existence of pharmacy as a distinct scientific tech- 
nical occupation. 



PHARMACOPCEIAS 375 

568. Working formulas are given by the pharmacopoeia for 
preparations the character of which depends upon the 
materials and manipulations almost entirely, but the pharma- 
copoeia does not give working processes for substances of 
definite chemical composition which may be made in various 
ways, and the character of which can be readily ascertained 
by tests. 

The best assurance that tincture of rhubarb is in every way 
right would be derived from the use of perfect rhubarb and 
the conscientious and skillful application of the pharma- 
copoeial directions in making it. If the pharmacist makes 
the preparation himself and possesses the requisite knowl- 
edge and skill, he will know of his own knowledge that the 
preparation is what it ought to be; but if he buys tincture 
of rhubarb made by some one else, there are no tests known 
by which the quality of the preparation can be certainly 
verified by himself, and he is then reduced to the necessity 
of depending upon the skill and knowledge of the manu- 
facturer, and must take for granted that no mistake has been 
made nor any omission. The pharmacist who makes no 
pharmaceutical preparations, but simply dispenses the prod- 
ucts of others, is not in a position to guarantee the satis- 
factory character of his materials. Every detail mentioned 
in the pharmacopoeial directions for making any given prep- 
aration must be assumed to be necessary, and any modi- 
fication or disobedience of directions usually results in failure 
to a greater or less extent. 

569. All pharmacopoeias contain certain general directions, 
usually placed in front of the body of the text enumerating 
the medicinal substances. To illustrate the general principles 
or rules, the following extracts from the Norwegian Pharma- 
copoeia will serve our purpose: The introductory to the 
Norwegian Pharmacopoeia requires that the metric system 
shall be used, and it says that whenever the word parts is 



376 A CORRESPONDENCE COURSE IN PHARMACY 

employed in working formulas, it shall be interpreted to 
mean parts by weight. 

It orders that the thermometer of Celsius shall be used, 
and that the expression "common temperature" must be 
understood to be about 15°. 

It orders that the specific weight of liquids be taken at a 
temperature of 15° and that the number employed to 
designate the specific weight shall refer to water of the same 
temperature as the unit of expression. 

It explains that maceration is to be conducted at a tem- 
perature of from 15° to 25° and digestion at a temperature 
of from 30° to 45°. 

It orders that wherever water is directed to be used, dis- 
tilled water only shall be employed. 

It gives directions for the collection, drying and preserva- 
tion of plant substances, saying that unless otherwise directed, 
roots, rhizomes and tubers shall be collected in the spring 
before the leaves are fully developed, or in the fall when the 
plants whither, and that such drugs shall be freed from 
adhering dirt and other foreign substances before being dried. 
Barks are ordered to be preferably collected in the spring. 
Roots and herbs are to be collected when fully developed and, 
as a rule, at the time the flowers begin to expand. Flowers 
are to be collected when fully developed, and fruits and seeds 
when full-grown and mature. It orders that all plant drugs 
be collected in dry weather. It gives directions for drying 
the plant drugs at a temperature not exceeding 65°, and 
orders that these drugs be kept in well closed receptacles and 
protected against light and moisture. 

It gives directions concerning the comminution and 
powdering of drugs. 

It orders that every pharmacy must be provided with 
the facilities, apparatus and reagents necessary in earry- 
ing out the directions of the pharmacopoeia for the prep- 



PHARMACOPOEIAS 377 

aration, preservation and testing of all medicinal sub- 
stances. 

It orders that all containers in the pharmacy shall be pro- 
vided with labels conforming to the pharmacopceial Latinic 
nomenclature; that containers in which poisonous remedies 
are kept shall have labels with red letters and all others 
labels with black lettering. 

It provides that substances which are volatile, or which are 
liable to attract moisture or to become altered under the 
influence of air or light, must be preserved in well closed 
receptacles, impervious to light. 

It says that the table of maximum doses given in the 
pharmacopoeia must be understood to refer to doses safe 
when administered to adults. 

It finally declares that all medicinal substances must be in 
satisfactory conformity to all the requirements of the 
pharmacopoeia, and that medicinal preparations for which 
the pharmacopoeia gives detailed directions of preparation 
must be made by the pharmacists themselves and not obtained 
from manufacturers. 

Test Questions 

1. When did the third national convention for revising 
the American Pharmacopoeia meet, and in what State ? 

2. How is the Pharmacopceial Convention constituted ? 

3. When did the convention meet last ? 

4. What is the difference between the Pharmacopceial 
Convention and the Pharmacopceial Committee of Revision? 

5. Of how many members does the Revision Committee 
consist and how are those members selected ? 

6. What is the scope of a pharmacopoeia? 

7. What kinds of simple substances may be properly 
described in a pharmacopoeia ? 

8. What substances of definite chemical composition may 



378 A CORRESPONDENCE COURSE IK PHARMACY 

it properly include, and what kinds of pharmaceutical prep- 
arations are legitimate in a pharmacopoeia ? 

9. What kinds of medicines in common use are unfit to 
be included in a pharmacopoeia ? 

10. Is there any reason for including in a pharmacopoeia 
an entirely new remedy not yet sufficiently tried to establish 
its value ? 

11. What is the principal object of a pharmacopoeia ? 

12. How is that object attained ? 

13. Is it possible to fix the strength of a pharmaceutical 
preparation made out of a plant drug ? If so, how ? 

14. In analyzing the text of the pharmacopoeia, how can 
the different parts of the text be classified with regard to 
their uses ? 

15. What is the origin of the Latinic titles of the plant 
drugs of the pharmacopoeia ? 

16. How are the English technical titles of plant drugs 
obtained ? 

17. In what cases are the Latinic titles of plant drugs 
made to consist of more than one word ? 

18. State briefly the character of the definition of a plant 
drug. 

19. What definitions are given for chemical compounds? 

20. What are the objects of the descriptions? 

21. In what cases of official medicines are the definitions 
and descriptions absent from the pharmacopceial text ? 

22. How are the tests in the pharmacopoeia classified ? 

23. For what kinds of preparations does the pharmacopoeia 
give explicit methods of production ? 



LESSON TWENTY-FOUR 

XXXIV 

The Latinic Nomenclature of the Pharmacopoeia 

570. About five hundred words have furnished the one 
thousand titles in the United States Pharmacopoeia, and of 
these five hundred words, about one hundred are simply 
modifications or derivatives of other words included in the 
five hundred. Most of these words are derived from Greek 
roots, others from Latin roots, or from Arabic, and others 
again from different languages and names of places and men. 
All of the titles so far as practicable have been given a 
Latinic form by changing their endings. 

A knowledge of the Latin language is not necessary to 
understand the Latinic nomenclature; in fact, some of the 
real Latin words used in the technical terminology of phar- 
macy do not have at all the same meaning when so used as 
they had or have in the Latin language ; but to learn the 
construction of the pharmacopoeial nomenclature and how 
to use it and abbreviate it correctly requires a knowledge of 
Latin declensions and of certain rules of abbreviation and 
other rules. 

571. The most common endings of the Latinic titles are 
us, a, urn, as and is. These nominative endings follow the 
Latin declensions. 

The only title now at all used which follows the fifth 
declension is the word species. This is. plural and its geni- 
tive is specierum. 

379 



380 A CORRESPONDENCE COURSE IN PHARMACY 

There are five titles following thefoitrth declension. These 
are cornus, ficus, quercus, fructus and spiritus. Their 
genitives are identical with their nominatives. 

All titles ending in a in the nominative follow the first 
declension and their genitive ending is ce, except that titles 
of Greek origin ending in ma in the nominative follow the 
third declension, having the genitive ending matis, as, for 
instance, gramma, gram'matis ; physostigma, physostig'matis ; 
aspidosperma, aspidosper'matis ; theobroma, theobro'matis ; 
enema, ene'matis. 

All titles ending in us or um follow the second declen- 
sion and have the ending i in the genitive. Certain 
words of Greek origin ending in os and on are treated 
as if their endings were us or um. The following exam- 
ples of titles following the second declension will suffice: 
oxidum, oxidi; rubus, rubi; prinos, prini; haematoxylon, 
hgematoxyli. 

All words that do not follow the declensions already men- 
tioned must, of course, follow the third declension if they 
are declined at all. Words following the third declension 
have very many different endings. Many of them have the 
nominative endings as and is, as, for instance, sulphas, nitras, 
sulphis, nitris. Other examples of words following the 
third declension are as follows : 

lotio pix 

tuber adeps 

radix juglans 

flos ' piper 

semen mel 

borax mas 

calx lac 

The genitive ending of words following the third declension 
is is. It is easy to change the nominative to the genitive 



THE LATINIC NOMENCLATURE OF THE PHARMACOPEIA 381 



except in the third declension, where it is frequently necessary 
to introduce additional letters or to change both consonants 
and vowels of the nominative in order to make the genitive 
form sound euphonious. The following titles following the 
third declension are among those contained in the American 
Pharmacopoeia : 



Nominative 


Genitive 


English Name 


adeps 


adipis 


lard 


aether 


astheris 


ether 


alumen 


aluminis 


alum 


anthemis 


anthemidis 


Roman chamomile 


calx 


calcis 


lime 


cannabis 


cannabis 


hemp 


cantharis 


cantharidis 


Spanish fly 


carbo 


carbonis 


charcoal 


colocynthis 


colocynthidis 


colocynth 


confectio 


confectionis 


confection 


digitalis 


digitalis 


foxglove 


fel 


fellis 


bile 


hamamelis 


hamamelis 


witch hazel 


hydrastis 


hydrastis 


golden seal 


iris 


iridis 


blue flag 


juglans 


juglandis 


butternut 


limon 


limonis 


lemon 


liquor 


liquoris 


liquid 


macis 


macidis 


mace 


mel 


mellis 


honey 


mucilago 


mucilaginis 


mucilage 


nux 


nucis 


nut 


sinapis 


sinapis 


mustard 


theobroma 


theobromatis 


chocolate 


pepo 


peponis 


pumpkin 


physostigma 


physostigmatis 


Calobar bean 


piper 


piperis 


pepper 


pix 


picis 


tar 


pulvis 


pulveris 


powder 


rhus 


rhois 


sumach 


rumex 


rumicis 


yellow dock 


sapo 


saponis 


soap 



382 



A CORRESPONDENCE COURSE IN PHARMACY 



Nominative 


Genitive 


English Name 


sassafras 


sassafras 


sassafras 


styrax 


styracis 


storax 


sulphur 


sulphuris 


sulphur 


trituratio 


triturationis 


trituration 


acetas 


acetatis 


acetate 


arsenis 


arsenitis 


arsenite 


benzoas 


benzoatis 


benzoate 


boras 


boratis 


borate 


carbolas 


carbolatis 


carbolate 


chromas 


Chromatis 


chromate 


citras 


citratis 


citrate 


hydrobromas 


hydrobromatis 


hydrobromate 


hydrochloras 


hydrochloratis 


hydro chlorate 


hypophosphis 


hypophosphitis 


hypophosphite 


lactas 


lactatis 


lactate 


nitras 


nitratis 


• nitrate 


nitris 


nitritis 


nitrite 


oleas 


oleatis 


oleate 


phosphas 


phosphatis 


phosphate 


pyrophosphas 


pyrophosphatis 


pyrophosphate 


salicylas 


salicylatis 


salicylate 


sulphas 


sulphatis 


sulphate 


sulphis 


sulphitis 


sulphite 


tartras 


tartratis 


tartrate 


cortex 


corticis 


bark 


flores 


florum 


flowers 


radix 


radicis 


root 


semen 


seminis 


seed 


semina 


seminum 


seeds 



572. The Latinic titles of the inorganic chemical com- 
pounds are, of course, constructed out of the names of the 
elements. These names of the elements in Latinic form will 
be found on pages 46-48 of this book. It will be noticed that 
the Latinic names of all the elements of which any com- 
pounds are employed in pharmacy have the ending um or 
turn in the nominative, and that they accordingly must 
follow the second declension, except the name phosphorus 



THE LATINIC NOMENCLATURE OF THE PHARMACOPOEIA 383 

with the genitive phosphori, and the name sulphur with the 
genitive sulphuris. 

In constructing Latinic titles for binary compounds the 
English ending ide is simply changed to idum, or, in other 
words, the final e is changed to um. Thus, a chloride is 
called cliloridum; a bromide," bromidum; an iodide, iodidum; 
an oxide, oxidum; a sulphide, sulphidum, etc. 

The Latinic titles of true salts are constructed by simply 
changing the English ending ate to as and the English 
ending ite to is. Thus, arsenate is called arsenas; 
arsenite, arsenis; carbonate, carbonas; chlorate, cliloras; 
bicarbonate, bicarbonas; hypophosphite, hypopliospliis; 
subsulphate, subsulplias; permanganate, per mang anas; 
thio-sulphate, tliiosulplias, etc. The student will readily 
understand that these arbitrarily constructed Latinic titles 
are in no sense Latin words. 

573. Having learned how to construct the Latinic generic 
titles for classes of binary compounds and of salts, we may 
now construct the complete titles of specific substances. 
We do this as follows : As in naming a binary compound in 
English we first mention the positive element and then the 
generic title of the compound constructed out of the negative 
element with the ending ide, so, in constructing the Latinic 
title, we give the Latinic name of the positive element with 
its genitive ending and then the Latinic name of the generic 
title of the compound named; as, for instance, in naming 
iron chloride, we would say ferri cliloridum; potassium 
hydroxide would be potassii liydr oxidum; sodium iodide 
would be sodii iodidum; copper sulphate would be cupri 
sutyhas; magnesium sulphite would be magnesii sulphis; 
sodium bicarbonate would be sodii bicarbonas; calcium hypo- 
chlorite would be calcii hypochloris, etc. 

In constructing titles for preparations of the inorganic 
compounds, we must, of course, use the genitive of the entire 



384 A CORRESPONDENCE COURSE IN PHARMACY 

title of the compound. Thus, solution of potassium hydrox- 
ide is called liquor potassii hydroxidi; solution of chloride 
of iron becomes liquor ferri chloridi; solution of nitrate of 
mercury is called liquor hydrargyri nitratis; syrup of iodide 
of iron is called syrupus ferri iodidi; compound syrup of 
the hypophosphites is called syrupus hypophosphitum 
coinjjositus. 

574. The Latinic title for acid is acidum. To this title 
we add an adjective indicating the hind of acid. The 
English adjectives ending in ic have corresponding Latinic 
equivalents ending in icus or ica or icum, according to the 
gender. English adjectives ending in ous have Latinic 
equivalents ending in osus, osa, osum. As the word acidum 
is neuter, the adjective used in naming acids must also be 
neuter. Hence, acetic acid is called acidum aceticum; 
arsenous acid is called acidum arsenosum; benzoic acid is 
called acidum benzoicum; boric acid, acidum tor icum; citric 
acid, acidum citricum; gallic acid, acidum gallicum; hydri- 
odic acid, acidum hydriodicum; hydrobromic acid, acidum 
hydrobromicum; hydrochloric acid, acidum hydrochloricum; 
hydrocyanic acid, acidum hydrocyanicum; hypophosphorous 
acid, acidum hypophosphorosum; lactic acid, acidum lacticum; 
nitric acid, acidum nitricum; nitrohydrochloric acid, acidum 
nitrohydrochloricum; oleic acid, acidum oleicumj phosphoric 
acid, acidum phosphor icum; salicylic acid, acidum sali- 
cylicum; sulphuric acid, acidum sulphuricum; sulphurous 
acid, acidum sulphur osum; tannic acid, acidum tannicum; 
tartaric acid, acidum tartaricum. 

575. In naming pharmaceutical preparations of plant 
drugs and other medicinal substances, the generic title of 
the class to which the preparation belongs is always given 
first. We may say in English "compound solution of iodine," 
but in giving the Latinic title of that preparation we would 
not put the adjective first, but last. The title liquor is 



THE LATINIC NOMENCLATURE OF THE PHARMACOPEIA 385 



placed first and so the title of the compound solution of 
iodine becomes liquor iodi compositus. We say "aromatic 
spirit of ammonia" in English, but in Latin the title is 
spiritus ammonim aromaticus. We say "heavy magnesia" in 
English, but we say magnesia ponder osa in Latin, because 
we always put the adjective last in any Latinic title. In 
naming extracts, tinctures, pills, powders, etc., we put these 
generic titles first and then give in the genitive the name 
of the drug or drugs from which the preparation is made. 
Hence, the title of extract of rhubarb must be extr actum 
rhei, and of tincture of rhubarb tinctura rliei. 

576. The Latinic titles of classes of pharmaceutical prep- 
arations in the American Pharmacopoeia are as follows : 



acetum 


vinegar 


aqua 


water 


ceratum 


cerate 


charta 


paper 


confectio 


confection 


decoctum 


decoction 


emplastrum 


plaster 


emulsum 


emulsion 


extractum 


extract 


fluidextractum 


fluidextract 


glyceritum 


glycerite 


infusum 


infusion 


linimentum 


liniment 


liquor 


liquor ("solution") 


massa 


mass 


mistura 


mixture 


mucilago 


mucilage 


oleatum 


oleate 


oleoresina 


oleoresin 


oleum 


oil 


pilula 


pill 


pilulae 


pills 


pulvis 


powder 


resina 


resin 


spiritus 


spirit 



SSiJ 



A CORRESPONDENCE COURSE IN PHARMACY 



suppositorium 

suppositoria 

syrupus 

tinctura 

trituratio 

trochiscus 

trochisci 

unguentum 

vinum 



suppository 

suppositories 

syrup 

tincture 

trituration 

troche 

troches 

ointment 

wine 



577. Certain Latinic adjectives are employed in pharma- 
ceutical nomenclature to so great an extent that the student 
must learn them. They are the following: 



English Form 




Latinic Forms 






Masculine 


Feminine 


Neuter 


animal 


animalis 


animalis 


animale 


vegetable 


vegetabilis 


vegetabilis 


vegetabile 


soft 


mollis 


mollis 


molle 


flexible 


flexilis 


flexilis 


flexile 


mild 


mitis 


mitis 


mite . 


volatile 


volatilis 


volatilis 


volatile 


green 


viridis 


viridis 


viride 


sweet 


dulcis 


dulcis 


dulce 


strong 


fortis 


fortis 


forte 


common 


communis 


communis 


commune 


glacial 


glacialis 


glacialis 


glaciale 


antimonial 


antimonialis 


antimonialis 


antimoniale 


simple 


simplex 


simplex 


simplex 


compound 


compositus 


composita 


compositum 


cut 


incisus 


incisa 


incisum 


contused 


contusus 


contusa 


contusum 


hard 


durus 


dura 


durum 


fluid 


fluidus 


fluida 


fluidum 


liquid 


liquidus 


liquida 


liquidum 


fused 


fusus 


fusa 


fusum 


heavy 


ponderosus 


ponderosa 


ponderosum 


dry 


siccus 


sicca 


siccum 


dried 


exsiccatus 


exsiccata 


exsiccatum 


white 


albus 


alba 


album 


yellow 


flavus 


flava 


flavum 


red 


ruber 


rubra 


rubrum 



THE LATINIC NOMENCLATURE OE THE PHARMACOPOEIA 387 



English Form 




Latinic Forms 




Masculine 


Feminine 


Neuter 


black 


niger 


nigra 


nigrum 


decolorized 


decoloratus 


decolorata 


decoloratum 


deodorized 


deodoratus 


deodorata 


deodoratum 


bitter 


amarus 


amara 


amarum 


aromatic 


aromaticus 


aromatica 


aromaticum 


absolute 


absolutus 


absoluta 


absolutum 


concentrated 


concentratus 


concentrata 


concentratum 


diluted 


dilutus 


diluta 


dilutum 


inspissated 


inspissatus 


inspissata 


inspissatum 


crude 


crudus 


cruda 


crudum 


pure 


purus 


pura 


purum 


impure 


impurus 


impura 


impurum 


purified 


purificatus 


purificata 


purificatum 


washed 


lotus 


lota 


lotum 


skinned 


despumatus 


despumata 


despumatum 


expressed 


expressus 


expressa 


expressum 


prepared 


prseparatus 


prseparata 


praeparatum 


granulated 


granulatus 


granulata 


granulatum 


crystallized 


crystallisatus 


crystallisata 


crystallisatum 


sublimed 


sublimatus 


sublimata 


sublimatum - 


distilled 


destillatus 


destillata 


destillatum 


rectified 


rectificatus 


rectificata 


rectificatum 


corrosive 


corrosivus 


corrosiva 


corrosivum 


aqueous 


aquosus 


aquosa 


aquosum 


alcoholic 


alcoholicus 


alcoholica 


alcoholicum 


reduced 


reductus 


reducta ■ 


reductum 


sulphurated 


sulphuratus 


sulphurata 


sulphuratum 


monobromated 


monobromatus 


monobromata 


. monobromatun 


ferric 


ferricus 


ferrica 


ferricum 


mercuric 


hydrargyricus 


hydrargyrica 


hydrargyricum 


nitrous 


nitrosus 


nitrosa 


nitrosum 


ferrous 


ferrosus 


ferrosa 


ferrosum 


mercurous 


mercurosus 


mercurosa 


mercurosum 


effervescent 


effervescens 


effervescens 


effervescens 


deliquescent 


deliquescens 


deliquescens 


deliquescens 



578. In naming pills, the pharmacopoeia uses the plural in 
the Latinic title. Compound cathartic pills are therefore 
called pilulce catharticce composites. The genitive of this 



388 



A CORRESPONDENCE COURSE IN PHARMACY 



title is pilularum catharticarum compositarum, because the 
genitive plural in the first declension ends in arum. 

579. Very few, if any, of the Latinic labels found upon 
the shop bottles in the drug stores are correctly abbreviated, 
if abbreviated in any way. Latin abbreviations do not 
follow the same rules as English abbreviations. The rules 
for abbreviations of Latin words are as follows : 

No word should be abbreviated at all unless at least three 
letters are omitted, and all letters omitted in any abbreviation 
should be at the end of the word. The last letter written 
should always be a consonant, .and the first letter omitted 
should always be a vowel. The letter u is treated as a vowel 
if it stands before a consonant; it is treated as if it were 
the consonant v if it stands in front of the vowel e or the 
vowel t, or whenever pronounced like v. Hence, the word 
unguentum can be abbreviated ungu., but it cannot be 
abbreviated ung. The following examples of correct and 
incorrect abbreviations will illustrate the rules : 





Correct 


Incorrect 


r ords in Full 


Abbreviations 


Abbreviations 


tinctura 


tinct. 


tin. tine. 


emplastrum 


empl. 


emp. emplas, 


extractum 


extr. 


ext. 


acetatis 


acet. 


acetat 


potassii 


pot. 


potas. 


spiritus 


spir. 


sp. spirit. 


syrupus 


syr. 


syru. 



580. Among the words that should never be abbreviated 
are acidum, aqua, aether, iodum, cerium, opium, oleum, 
aloes, aurum, barium, bromum, calcium, ferrum, cuprum, 
lithium, zincum, plumbum, acacia, cera, scilla, rheum, etc., 
for reasons understood from the rules given. 

Abbreviations which are ambiguous should never be made. 
The title aqua acidi carb. if written upon a prescription may 



THE LATINTC NOMESTCLATUEE OF THE PHAEMACOPCEIA 389 

stand for carbolic acid water or for carbonic acid water. 
The abbreviation chlor. hydr. may mean chloral hydrate or 
calomel or corrosive sublimate. Sodii chlor. may mean either 
sodium chloride or sodium chlorate. Oal. may mean calumba 
or it may mean calendula or calycanthus. Col. may mean 
colchicum or columbo or collinsonia, since it is well known 
that abbreviations are more frequently incorrect than correct. 
The abbreviation aq. am. may be a poor attempt at abbrevi- 
ating aqua ammonise or aqua amygdalae; sulph. may be an 
abbreviation of sulphatis or it may be an abbreviation of 
sulphidi; elat. may be an abbreviation of elaterium or an 
abbreviation of elaterinum. 

581. Several of the titles of drugs are indeclinable. All 
words ending in 0?, yl, al and ul are generally treated as 
indeclinable, as, for example, alcohol, menthol, phenol, 
thymol, benzol, amyl, aethyl, methyl, phenyl, chloral and 
sumbul. Other indeclinable words are some that have been 
derived from the languages of savage tribes and cannot be 
conveniently given a Latinic form, as, for example, azedarach, 
buchu, catechu, coca, curare, elemi, jaborandi, kamala, 
kino, kousso, matico and sago. 

Test Questions 

1. Why are the principal titles of the pharmacopoeial 
drugs and preparations said to be Latinic ? 

2. Name the Latinic titles following the fifth declen- 
sion. 

3. Name those following the fourth declension. 

4. State what titles follow the first declension. 

5. What titles follow the second declension ? 

6. What titles follow the third declension ? 

7. What are the nominative and genitive endings of the 
respective declensions ? 



390 A CORRESPONDENCE COURSE IN" PHARMACY 

8. Give the genitives of the following titles: Sal, 
berberis, cortex, nitras, sulphis, borax, rumex, juglans, 
zingiber, gargarisma, cannabis, liquor, flores, semina, 
folia. 

9. Write in full the Latinic titles of the following articles, 
also the proper abbreviations of those Latinic titles : tincture 
of aconite, lard oil, oleoresin of male fern, nuidextract of 
buchu, extract of Cannabis Indica, cerate of cantharides, 
infusion of digitalis, licorice root, wine of aloes, nuidextract 
of nux vomica, spirit of myristica, extract of physostigma, 
emulsion of almond, oleoresin of pepper, resin of podophyl- 
lum, syrup of wild cherry, oak bark, glycerite of hydrastis, 
decoction of sarsaparilla, vinegar of squill, compound 
infusion of senna, extract of stramonium seed, ammoniated 
tincture of valerian, nuidextract of veratrum viride, aro- 
matic spirit of ammonia, the seed of aspidosperma, herb 
of tussilago, vegetable cathartic pills, suppositories of opium, 
ointment of nitrate of mercury, nitrate of silver, acetate of 
lead, oxide of mercury, chloride of gold, sulphate of copper, 
dioxide of manganese, iodide of arsenic, hydrochloric acid, 
hydrocyanic acid, boric acid, arsenous acid, sulphurous acid, 
aromatic sulphuric acid, zinc carbonate, zinc phosphide, 
oxide of calcium, hydroxide of aluminum, red oxide of 
mercury, yellow iodide of mercury, black sulphide of anti- 
mony, sodium hydroxide, ferric hydroxide, ferrous sulphate, 
ferric sulphate, ammonium chloride, potassium bromate, 
solution of chloride of iron, solution of ferric sulphate, mild 
chloride of mercury, corrosive chloride of mercury, syrup 
of ferrous iodide, chlorate of potassium, valerate of zinc, 
dried sulphate of iron, saccharated carbonate of iron, bicar- 
bonate of sodium, permanganate of potassium, syrup of 
lactophosphate of calcium, compound syrup of the hypo- 
phosphites, chlorine, bromine, iodine, carbon, antimony, 
carbonic acid water, solution of hydrogen dioxide, glacial 



THE LATINTC NOMENCLATURE OF THE PHAEMACOPCEIA 391 

acetic acid, calcium hypochlorite, sodium thio-sulphate, 
potassium chromate, bitartrate of potassium, oxalate of iron, 
chloride of gold and sodium, tartrate of potassium and 
sodium, saccharated iodide of iron, sulphurated potassa, 
sulphurated antimony, yellow subsulphate of mercury, 
aluminum and ammonium sulphate, alum, dried alum, 
precipitated phosphate of calcium, granulated sulphate of 
copper, crystallized nitrate of silver, fused nitrate of silver, 
diluted hypophosphorous acid, soluble phosphate of iron, 
dried sodium carbonate, subnitrate of bismuth, potassium 
dichromate, solution of potassium arsenite, solution of 
arsenous acid, solution of iodide of mercury and arsenic, 
oleate of mercury, tartrate of iron and potassium, citrate of 
iron and quinine, solution of citrate of magnesium, mercury 
with chalk, pure hydrochloric acid, purified antimony sul- 
phide, deodorized alcohol, hard soap, soft soap, sublimed 
calomel, distilled water, expressed oil of nutmeg, volatile oil 
of mustard, alcohol, extract of belladonna, washed sulphur, 
prepared chalk, prepared calcium carbonate, sublimed 
sulphur, heavy magnesia, precipitated oxide of mercury, 
precipitated sulphate of iron, strychnine, morphine, cocaine, 
salicin, lupulin, aconitine, ether, acetic ether, absolute 
alcohol, glycerin, pepsin, sugar, milk sugar, chloral, purified 
chloroform, quinine sulphate, quinine hydrochloride, mor- 
phine hydrochloride, physostigmine salicylate, hyoscine 
hydrobromide, syrup of hydriodic acid, solution of acetate 
of ammonium, lime solution, compound solution of iodine, 
solution of chlorinated soda, ointment of subacetate of lead, 
confection of senna, resin of jalap, powder of ipecac and 
opium, trituration of morphine sulphate, troches of licorice 
and opium, mercury mass, potassium nitrate paper, com- 
pound iron mixture, peppermint water, mucilage of traga- 
canth, compound tincture of cinchona, compound morphine 
powder, camphorated soap liniment, chlorine water, aqueous 



392 A CORRESPONDENCE COURSE IN PHARMACY 

extract of aloes, aromatic fluidextract, fluidextract of bitter 
orange peel, fluidextract of colchicnm seed, saecharated 
pepsin, antimonial powder, spirit of nitrous ether, tincture 
of arnica flowers, tincture of kino, deodorized tincture of 
opium, tincture of deodorized opium, tincture of green soap, 
ointment of ammoniated mercury, effervescent citrate of 
magnesium. 



LESSON TWENTY-FIVE 

XXXV 

The Pharmacopoeia of the United States 
Eighth Revision — A. 

In order to acquire sufficient familiarity with the style, 
scope and contents of the pharmacopoeia, the student should 
study certain portions of it as indicated in the following 
suggestions: 

Read the titles and definitions, including the percentage 
strength, of acetic acid, diluted acetic acid, glacial acetic 
acid, diluted hydriodic acid, diluted hydrobromic acid, 
hydrochloric acid, diluted hydrochloric acid, diluted hydro- 
cyanic acid, hypophosphorous acid, diluted hypophosphorous 
acid, lactic acid, nitric acid, diluted nitric acid, phosphoric 
acid, diluted phosphoric acid, sulphuric acid, diluted sul- 
phuric acid, sulphurous acid. 

Learn the definitions and percentage strength of ether, 
acetic ether, alcohol, absolute alcohol, diluted alcohol, 
ammonia water, stronger ammonia water, solution of arsen- 
ous acid, solution of ammonium acetate, solution of arsenous 
and mercuric iodides, lime water, chlorine water, solution of 
ferric chloride, solution of ferric subsulphate, solution of 
ferric sulphate, solution of formaldehyde, solution of mer- 
curic nitrate, compound solution of iodine, solution of lead 
subsulphate, diluted solution of lead subsulphate, solution 
of potassium arsenite, solution of potassium hydroxide, 
solution of sodium arsenate, solution of sodium hydroxide 
and solution of zinc chloride. 

393 



394 A CORRESPONDENCE COURSE IN PHARMACY 

Eead the methods of preparation of vinegar of opium and 
vinegar of squill. 

Read the general paragraph concerning waters on page 49 
and the methods of preparation of the aromatic waters, from 
bitter almond water to rose water. 

Study the formulas for the preparation of cerates on 
pages 93-95. 

Read the processes of preparation of the collodions on 
pages 113 and 114, and look up the definition of pyroxylin 
in the proper place. 

Read the formulas for confections on page 115; the 
general directions for the preparation of decoctions and infu- 
sions, suppositories and tinctures of fresh drugs. 

Read the formulas for plasters on pages 124-127. 

Study the emulsions, pages 127-130. 

Test Questions 

1. What is the percentage strength of the diluted acids 
of the pharmacopoeia? 

2. Does the percentage strength of any one of the 
pharmacopoeial acids bear a simple relation to the molecular 
weight? 

3. How many pounds of diluted hypophosphorous acid 
can be made from ten pounds of hypophosphorous acid? 

4. What is the difference between the undiluted nitric 
acid of the pharmacopoeia and absolute nitric acid? 

5. What is the difference between absolute ether and 
official ether? 

6. Give the molecular formulas of ether, acetic ether 
and alcohol. 

7. How is diluted alcohol made? 

8. What is the percentage strength of diluted alcohol 
and the percentage strength of alcohol? 

9. In what proportions would you mix official alcohol 



THE PHARMACOPOEIA OF THE UNITED STATES — A. 395 

and official diluted alcohol to produce an alcohol of 60% 
strength? 

10. What is them olecular weight of ammonia, and what 
is the molecular weight of ammonium hydroxide? 

11. What percentage of ammonium hydroxide is con- 
tained in a solution containing 10% of ammonia? 

12. How much stronger ammonia water is necessary to 
make twenty-eight pounds of ammonia water? 

13. What is the difference between arsenous oxide and 
arsenous acid? 

14. How much arsenous acid is contained in one hundred 
parts of a solution made out of one part of arsenous oxide? 

15. What percentage of acetic acid is contained in the 
official solution of ammonium acetate? 

16. What percentage of the element arsenic is contained 
in the solution of arsenous and mercuric iodides, and what 
percentage of mercury? 

17. How much calcium hydroxide will be formed by 
twelve grams of lime? 

18. What is chlorine water, according to the new pharma- 
copoeia? 

19. Crystallized ferric chloride is FeCl 3 -f 6H 2 0. How 
much crystallized ferric cholride can be made from one 
hundred parts of the official solution? 

20. What is the principal difference between solution 
of ferric subsulphate and solution of ferric sulphate, as 
shown by the proportions of the materials employed in their 
preparation? 

21. What is pharmacopoeial formaldehyde solution? 

22. What is formed besides mercuric nitrate when mer- 
curic oxide is dissolved in nitric acid? 

23. What is compound solution of iodine? 

24. What is solution of magnesium citrate? 

25. How many ounces of diluted solution of load subace- 



396 A CORRESPONDENCE COURSE IN PHARMACY 

tate can be made out of one ounce of the official solution 
of lead subacetate? 

26. What is the percentage of As in solution of potas- 
sium arsenite? 

27. How do you reconcile the proportions of potassium 
hydroxide and water in the formula for the preparation of 
solution of potassium hydroxide with the official state- 
ment of percentage strength of that solution? 

28. What proportions of sodium hydroxide and water 
are necessary to make one kilogram of a 5% solution? 

29. What is the percentage of Zn in the official solution 
of zinc chloride? 

30. By what process are the official vinegars made? 

31. In what respect does the process for the preparation 
of bitter almond water differ from the methods directed for 
the preparation of other aromatic waters? 

32. How wo aid you make a saturated solution of chloro- 
form in water? 

33. What aromatic waters of the pharmacopoeia are 
made by distillation? 

34. How is a saturated solution of camphor in water 
prepared? 

35. What waters of the pharmacopoeia are not aromatic 
waters? 

36. What resemblance do you find between the composi- 
tion of cantharides cerate and resin cerate? 

37. What cerates of the pharmacopoeia contain white 
petrolatum? 

38. Why is wool fat contained in the cerate of lead 
subacetate? 

39. What constitutes the body of the official collodions? 

40. How is the painful contraction of the collodion film 
left upon evaporation of an application of collodion prevented? 

41. What confections are retained in the pharmacopoeia? 



THE PHARMACOPOEIA OE THE UNITED STATES — A. 397 

42. State how decoctions are made. 

43. How are infusions made? 

44. What are the general directions of the pharmacopoeia 
relative to the preparation of suppositories? 

45. What is the general method directed by the pharma- 
copoeia for the preparation of tinctures of fresh vegetable 
drugs? 

46. What is adhesive plaster, according to the new 
pharmacopoeia? 

47. What official plasters are made from solid extracts? 

48. What is the new process for the preparation of lead 
plasters? 

49. Name the fixed oil emulsions, volatile oil emulsions, 
gum resin emulsions and seed emulsions of the pharma- 
copoeia. 

50. How is the emulsion of cod liver oil made? 

51. What resemblance do you note between the process 
for preparing emulsion of oil of turpentine and that for 
preparing emulsion of chloroform? 



LESSON TWENTY-SIX 
XXXVI 

The Pharmacopoeia of the United States — B. 

Study the working formulas for the preparation of solid 
extracts, pages 133-150. In studying these extracts, observe 
that some of them are made with water, others with undiluted 
alcohol, others with a mixture containing more alcohol than 
water, others with equal parts of alcohol and water, and still 
others with a menstruum consisting of more water than 
alcohol. Note which of these extracts are of pilular con- 
sistence and which of them are dry ; also which of the dry 
extracts are ordered to be powdered. Note that some of 
them are diluted with powdered sugar of milk and others 
with powdered licorice root. Note, also, that some of the 
solid extracts are of definite potency, being adjusted to a 
fixed percentage of alkaloidal contents. Learn, also, which 
of the solid extracts are prepared by the evaporation of fluid 
extracts. 

Next study the fluid extracts. Note which of them are 
made with undiluted alcohol and which are made with mix- 
tures of alcohol and water, containing either more alcohol 
than water, more water than alcohol, or equal volumes of 
alcohol and water. Also note which of the fluid extracts are 
ordered by the pharmacopoeia to be assayed and adjusted 
to a fixed standard of strength. 

Learn how the glycerites are made, as described on pages 
224-226. 

Bead the formulas for infusions on pages 247 and 248 and 

398 



THE PHARMACOPOEIA OE THE UNITED STATES — B. 399 

compare those formulas with the general directions beginning 
at the foot of page 246. 

Eead and compare with each other the formulas for lini- 
ments on pages 255-257. 

Examine the formulas for masses on page 286. 

Read the formulas for mixtures on pages 292 and 293, 
then study the mucilages on pages 296 and 297. 

Study the oleates on pages 300 and 301 and note that they 
are not preparations of definite chemical composition, but 
simply solutions of alkaloids in oleic acid and olive oil, 
except the oleate of mercury, which is a solution of oleate 
of mercury in oleic acid. 

Examine the formulas for oleoresins on pages 202-204 and 
observe that this class of preparations has been materially 
changed in the new revision of the pharmacopoeia, being 
now prepared with acetone instead of with ether. 

Read the titles and definitions of the oils. Note which of 
them are fixed oils and which are volatile oils, and which of 
them are not oils at all, although bearing that title. 

Compare the standards of strength of powdered opium, 
opium, deodorized opium and granulated opium on pages 328- 
331. 

Read the definition and description of pepsin and of 
pancreatin. 

Study the formulas for pills on pages 345-350. 

Study the formulas for compound powders on pages 368- 
371. 

Read the processes for the preparation of precipitated 
resins on pages 378-381. 

Read the formulas for spirits on pages 413-421. Note 
which of them are solutions of volatile oils in alcohol, which 
of them are alcoholic solutions of ether compounds, which 
of them are solutions of gases and which of them are well- 
known liquors. 



400 A CORRESPONDENCE COURSE IN" PHARMACY 

Read the formula for syrups, pages 435-448. Note 
which of them contain active medicinal agents and which of 
them are merely flavoring media. Also note which of the 
syrups are solutions of inorganic substances. 

Study the formulas for the preparation of tinctures on 
pages 453-485. Observe which of these tinctures are made 
with undiluted alcohol and which are made with mixtures 
of alcohol and water, containing more alcohol than water, 
those made with more water than alcohol and those made 
with official diluted alcohol. Also note what tinctures are 
made with aromatic spirit of ammonia. Learn which 
tinctures contain inorganic active constituents. Learn what 
tinctures are made from fluid extracts, and learn also what 
tinctures are assayed and adjusted to a definite standard of 
strength by that means. Learn what tinctures are of 5% 
and which are of 10%, 15% and 20% strength or other 
standards of strength, with reference to the kind of drug 
used. 

Read the general formula for triturations and the formula 
for trituration of elaterin. 

Study the formulas for troches on pages 486-489. 

Make yourself acquainted with ointments of the pharma- 
copoeia by reading the formulas for their preparation on 
pages 490-497. 

Read the formulas for the official wines on pages 501-503. 

Test Questions 

1. How much belladonna leaves is represented approxi- 
mately by one gram of the extract? 

2. What menstruum is used in the preparation of extract 
of aloes? 

3. What menstruum is used in preparing extract of 
cannabis indica? 

4. What is compound extract of colocynth? 



THE PHARMACPOEIA OF THE UNITED STATES — B. 401 

5. Enumerate the aqueous extracts of the pharmacopoeia. 

6. What solid extracts are prepared from fluid extracts? 

7. What extracts of the pharmacopoeia are prepared 
with acetic acid? 

8. How much powdered opium equals one gram of extract 
of opium? 

9. What powdered extracts are contained in the pharma- 
copoeia? 

10. Which of the official extracts are assayed? 

11. What fluid extracts are assayed? 

12. Are any of the official fluid extracts prepared with 
water? 

13. What fluid extracts are prepared with undiluted 
alcohol? 

14. Are there any fluid extracts in the pharmacopoeia 
which deviate from the rule that one cubic centimeter 
represents the activity of one gram of the drug? If so, 
which of them? 

15. In what fluid extracts is acetic acid contained? 

16. What is glycerite of starch? 

17. What is boroglycerin? 

18. In what respect does glycerite of hydrastis resemble 
the fluid extract of hydrastis? 

19. What glycerites of the pharmacopoeia are liquid 
glycerin solutions? 

20. How is infusion of digitalis made? 

21. In what respect does the formula for infusion of wild 
cherry deviate from the general directions for the prepara- 
tion of infusions? 

22. What is lime liniment? 

23. What is ammonia liniment? 

24. How is soap liniment prepared? 

25. Is the mass of ferrous carbonate a galenical or a 
chemical preparation? 



402 A CORRESPONDENCE COURSE IN PHARMACY 

26. How much mercury is contained in a pound of 
mercury mass? 

27. How is compound iron mixture made? 

28. Which of the official mucilages are liquid and which 
are solid? 

29. How much olive oil is contained in oleateof veratrine? 

30. In what respect do the methods of preparation ordered 
for oleoresin of cubeb and oleoresin of pepper differ from 
the directions given for the preparation of other oleoresins? 

31. Mention five fixed oils and ten volatile oils. 

32. What is the official standard of strength of pepsin? 

33. In which of the official pills is soap an ingredient? 

34. In which of the official pills is aloes contained? 

35. Which of the official pills contain iron? 

36. In what official pills do chemical reactions attend the 
method of preparation? 

37. What is aromatic powder? 

38. What are the most notable differences between the 
several processes for the preparation of the precipitated resins 
of the pharmacopoeia? 

39. Which of the spirits of the pharmacopoeia are not 
solutions of volatile oils? 

40. Which of the official syrups contain inorganic sub- 
stances? 

41. Which of them are made from fluid extracts? 

42. Enumerate the tinctures which are approximately of 
5% strength. 

43. Is it strictly true that when 100 Cc. of tincture is 
made from 20 grams of drug, that tincture is of 20% 
strength? If not, why not? 

44. How much tincture of nux vomica represents 1 Cc. of 
the fluid extract? 

45. What tinctures of the pharmacopoeia are mere mix- 
tures of the fluid extract with more or less diluted alcohol? 



THE PHARMACOPOEIA OF THE UNITED STATES — B. 403 

46. What is the percentage strength of tincture of aconite 
of the new pharmacopoeia? 

47. What is the percentage strength of the new tincture 
of veratrum? 

48. How would you make trituration of strychnine? 

49. What is the most common adhesive excipient ordered 
in the preparation of the troches of the pharmacopoeia? 

50. What is the maximum weight and the minimum 
weight of each of the official troches? 

51. What is "ointment"? 

52. What is diachylon ointment? 

53. How is rose water ointment made? 

54. What is the difference between mercurial ointment 
and blue ointment? 

55. Which of the official ointments are made of solid 
extracts? 

56. What official wines are made of fluid extracts? 

57. What official wines contain inorganic substances? 



LESSON TWENTY-SEVEN 

XXXVII 

The Pharmacopoeia of the United States — C. 

Learn the Latinic and English titles of the vegetable 
drugs of the pharmacopoeia by reading their titles and 
definitions, and note which of them are provided with an 
official standard of strength. Make separate lists of the 
vegetable drugs, consisting of (1) herbs, (2) leaves, (3) 
flowering tops, (4) flowers, (5) fruits, (6) seeds, (7) stems 
and barks, (8) woods, (9) rhizomes, bulbs and corms and (10) 
roots. 

Eead the formulas for the preparation- of benzoinated lard, 
purified aloes, molded silver nitrate, medicated silver nitrate, 
citrated caffeine, effervescent citrated caffeine, cataplasm of 
kaolin, mustard paper, adjuvant elixir, aromatic elixir, 
elixir of iron, quinine and strychnine, purified oxgall, 
glycerinated gelatin, effervescent lithium citrate, effervescent 
magnesium sulphate, clarified honey, honey of rose, soft 
soap, effervescent sodium phosphate, purified talc. 

To learn doses, make tables or lists of all the official 
remedies for which the pharmacopoeia gives doses, dividing 
the medicinal substances into groups according to the size 
of the doses, as follows: 

(a) Doses of less than 1 milligram. 

(b) 1 to 3 milligrams. 

(c) 4 to 10 milligrams. 

(d) 10 to 30 milligrams. 

(e) 30 to 100 milligrams. 

404 



THE PHABMACOPOEIA OF THE UNITED STATES — C. 405 



(f) 100 to 300 milligrams. 

(g) 300 to 1000 milligrams. 
(h) 1 to 3 grams. 

(i) 4 to 8 grams. 

(J) All substances having doses exceeding 8 grams. 

Test Questions 

1. What crude vegetable drugs of the pharmacopoeia are 
directed to be assayed? 



2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 
10. 
11. 
12. 
13. 
14. 
15. 
16. 
17. 
18. 
19. 
20. 
21. 
22. 
23. 
24. 
25. 
26. 



What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 
What 



s aconite? 

s althaea? 

s manna? 

s spermaceti? 

s cardamom? 

s buchu? 

s eucalyptus? 

s valerian? 

s copaiba? 

s aspidium? 

s lupulin? 

s jalap? 

s podophyllin and podophyllum? 

s cannabis indica? 

s myrrh? 

s rhubarb? 

s senega? 

s squill? 

s f rangula? 

s senna? 

s digitalis? 

s colocynth? 

s aloes? 

s ergot? 

s catechu? 



406 A CORRESPONDENCE COURSE IN PHARMACY 

27. What is gambir? 

28. What is kino? 

29. What is opium? - 

30. What is hyoscyamus? 

31. What is conium? 

32. What is nux vomica i 

33. What is veratrum? 

34. What is ipecacuanha? 

35. What is primus virginiana? 

36. How is purified aloes made? 

37. How are the effervescent salts of the pharmacopoeia 
made? 

38. Describe the preparation of purified oxgall? 

39. What is glycerinated gelatin? 

40. State the doses of aconitine, strychnine, morphine, 
diluted hydrocyanic acid, tincture of aconite, extract of nux 
vomica, extract of Calabar bean, extract of belladonna, fluid 
extract of colchicum, extract of conium, tincture of hyoscya- 
mus, aloin, elaterin, resin of podophyllum, extract of 
digitalis, tincture of cannabis indica, oil of turpentine, 
hydrated chloral. 



INDEX 



Abbreviations, 388, 389. 

Acacia (Gum Arabic), mucilage of, 334; 
use in pills, 321. 

Acetates, water-soluble, 225. 

Acids, 75-79; acetic, 83; action of heavy- 
metal upon, 137; attacked by metals, 
t 140; boric, 129, 203; carbonic, 84; 
'citric, 75; chemical action of, 129; 
chromic, 215; concentrated sulphuric 
dissolves, 139; concentrated nitric 
dissolves, 140; dilute nitric dissolves, 
139; dilute sulphuric dissolves, 138; 
experiments to prove opposite prop- 
erties, 78; hydrochloric dissolves, 
138; hydrocyanic, 4; hydroxyl, 77; 
inorganic, 75, 301; lactic, 75; Latinic 
titles for, 384; muriatic, 75; nitric, 
178; oxalic, 75; opposite properties 
of, 78; organic, definition of, 75; 
organic, sources of, 301,302; ortho- 
phosphoric, 120; phorphoric, 6; prop- 
erties and functions of, 80; sat-^ 
urated with metal, 143; sulphuric, 
inorganic, 6; sulphuric, forms salts, 
83 ; sulphuric, strength of, 129; tar- 
taric, 75. 

Adhesion, 33; properties of matter re- 
sulting from, 34. 

Air, 177; soluble in water, 297. 

Albumin, decomposes in air, 299; de- 
scription of, 298. 

Albuminoids, contained in drugs, 298. 

Alcohol, acts as a preservative, 298; 
composed of, 184; passes through 
plant membranes, 293; solubilities, 
226-228. 

Alkalis, properties of, 77, 78. 

Alkaloids, 309; kinds of, 310; sources 
of, 310, 311. 

Allotropy, 30. 

Althaea, powdered, 321. 

Alum, 84. 



Aluminum, compounds of, 221; decom- 
poses, 138; description of, 212; salts, 
212; sources of, 212. 

Amara, 303. 

Ammonia, definition of, 77 ; description 
of, 178. 

Ammonium, compounds of, 220; salts, 
178. 

Anion, 67. 

Anode, 67. 

Antimonite, 185. 

Antimony, compounds of, 222; decom- 
poses, 138; description of, 200; wine 
of, 351. 

Apprentices, 14. 

Aquae, 333. 

Aqua Regia, 196. 

Archimedes's Law, 255. 

Argon, definition of, 48. 

Arsenic, 138, 139; compounds of, 200, 
222: description of, 200. 

Atomic Hypothesis, 136. 

Atomic Valence, 87-93. 

Atomic Weight, 28, 57. 

Atoms, 26; algebraic combining num- 
bers of, 93-100; atomic hypothesis, 
56; atomic linking, 90; atomic mo- 
tion, 56; atomic valence, 87-93; atom- 
ic weights, 28, 57 ; changes in combin- 
ing numbers of, 151-153. 

Attraction, 24; molecular, 33. 

Avogadro's Law, 58. 

Barium, 210; compounds of, 220. 
Bases, 79; properties and functions of , 

80. 
Bead's, Specific Gravity, 256. 
Beauxite, 212. 

Benzoates, water-soluble, 226. 
Berthollet's Doctrine, 134, 135. 
Binary Compounds, 71-74. 
Bismuth, attacks, 139; compounds of , 



407 



408 



INDEX 



222; decomposes, 138; description of, 

218. 
Boiling Point, 37. 
Bonds, 89. 

Borates, soluble, 225. 
Borax, definition of, 121 ; formula for, 

209. 
Boron, adamantine, ignites in, 128 ; 

compound of, 203. 
Bougies, 328. 
Brass, 216. 
Brimstone, 198. 
Bromides, 73 ; soluble, 223. 
Bromine, decomposes, 127; description 

of, 197; exercises polarity, 131, 132; 

sources of, 197. 
Bunsen Burner, 267. 

Cadmium, compounds of, 221. 

Calcination, 268. 

Calcium, carbonate, 84; color of, 210; 

compounds of, 211, 220; hydroxide, 

84; oxide, 84, 85; sources of, 210. 
Calomel, 217. 
Carbohydrates, 291, 292. 
Carbon, chemical properties of, 201; 

compounds of, 201 , 202 ; description 

of, 201 ; dioxide, description of, 202; 

dioxide, forms of, 84, 202 ; monoxide, 

202. 
Carbonates, soluble, 225. 
Cataplasms, 323. 
Cellulose, 292. 

Cerates, 326; in Pharmacopoeia, 394. 
Cerium, compounds of, 221. 
Chalk, 84; mixture, 341. 
Chemical Nomenclature, 116; accords 

with periodic system, 172. 
Chemical Notation, system of, 103. 
Chemical Polarity, 66-69. 
Chemicals, inorganic, 6; medicinal, 5; 

organic, 6. 
Chemism, 40; affected by, 41. 
Chlorates, soluble, 224. 
Chlorides, definition of, 196; hydrogen, 

196; of alkali metals, 128; soluble, 

223; tincture of ferric, 348. 
Chlorine, chemical properties of, 196; 

decomposes, 127; description of, 195; 

exercises polarity, 131, 132; oxidiz- 



ing agent, 155, 158; sources of, 
195. 

Chromium, 215; compounds of, 215, 
221. 

Citrates, soluble, 225; wine of ferric 
citrate, 351. 

Clay, 212. 

Clerks, 13. 

Coal Oil, 202. 

Cobalt, compounds of, 221. 

Cohesion, 33; effects of heat upon, 36; 
of elements, 49 ; properties of matter 
resulting from, 34; states of, 34. 

Collodions, 342; in Pharmacopoeia, 
394. 

Combining Energy, 127-132. 

Combining Numbers, algebraic, 93-100, 
151-162. 

Combining Proportions, 53-56. 

Combustion, definition of, 41 ; in res- 
piration, 181, 183. 

Committee of Revision, 359. 

Compounds, binary, classes of, 72,73; 
binary, definition of, 71 ; binary, 
names of, 72; binary, titles for, 383; 
chemical, 27; chemical, titles of 
inorganic, 382, 383; ferric, 214; fer- 
rous, 214. 

Condensation Point, 37. 

Condensers, dome-shaped, 283; Lie- 
big's, 282; Mitscherlich's, 282, 283. 

Confections, 319; in Pharmacopoeia, 
394. 

Contusion, 269. 

Copper, compounds of, 216, 222; 
decomposes, 138; description of, 215; 
mines, 216. 

Corrosive Sublimate, 217. 

Cryolite, 212. 

Crystallization, 283, 284. 

Crystallizers, 284. 

Crystals, obtained by, 285. 

Cyanides, 224. 

Cyanogen, 202. 

Decoction, 276; formula for, 346; most 

common, 346, 347. 
Decompositions, double, 145. 
Density, 21; of gas, 37; of metals, 49; 

vapor densities, 58. 



INDEX 



409 



Dialysis, 292. 

Digestion, 275 ; effectiveness of, 275-276 ; 
temperature of, 275. 

Digitalis, 17. 

Displacement, circulatory, 273. 

Dissociation, 132. 

Distillation, 281; dry, 268. 

Doses, in Pharmacopoeia. 404. 

Drugs, animal, 5; constituents of, as 
guides in preparation, 294; crude, 4; 
fresh, 291; inorganic or mineral, 4; 
mechanical division of, 269; officinal, 
11; plant, 291; plant, chemical con- 
stituents of, 311, 312; plant, contain- 
ed in pharmacopoeias, 361; plant, 
definition of, 366, 367; plant, 
descriptions of, occurring in pharma- 
copoeias, 367-370; plant, titles of, 
364-366; vegetable, 5; vegetable, 
chemical constituents of, 291-312; 
vegetable, titles of, in Pharmaco- 
poeia, 404. 

Ductility, 49. 

Dulong and Petit's Law, 61. 

Dynamite. 178. 

Electricity, 23; conductors of, 50; 
effects of, 40. 

Electrode, 67. 

Electrolytes, 67. 

Electrolysis, 67. 

Electuaries, 319. 

Elements, 25; basic" function of, 131; 
chemical, 46; chemical, table of, 46- 
48 ; classification of, 26; cohesion of 
49 ; colors of, 49 ; density of, 49 ; ener- 
getic, 127; luster of, 49; positive and 
negative, 65; table of, 171. 

Elutriation, 271. 

Emulsions, 336; gum-resin, 338; hydro- 
cyanated, 338; in Pharmacopoeia, 
394; of chloroform, 341; of fixed oils, 
338, 339; of seeds, 336, 337. 

Endings, ic and ous, 117; of Latinic ti- 
tles, 379-382. 

Energy, 22; forms of, 23; indestructi- 
bility of, 22; kinetic, 24; potential, 
23, 24. 

Energy, combining, 127-132. 

Evaporation, 281. 



Excipients, 320; adhesive dry, 321 ; dry, 
321 ; wet or moist, 322. 

Exsiccation, 268. 

Extraction Methods, 274. 

Extracts, 345-357; fluid, 351, 352; in 
Pharmacopoeia, 398; kinds of, 8; of 
calabar bean, 17; solid, 353-355-, 
solid, added to plasters, 327. 

Factors, 132. 

Ferricyanides, 224. 

Ferrocyanides, 224. 

Filter, paper, 280. 

Filtration, 280. 

Fluids, 35. 

Fluorides, 73 ; of alkali metals, 128. 

Fluorine, 195. 

Formulas, constitutional or structural, 
109; empiric, 108; for perparations, 
in Pharmacopoeia, 404; magistral, 9; 
molecular, 108; molecular, how to 
write, 105-107, 109-116; symbolic, 
104; working, contained in Pharma- 
copoeia, 375. 

Frangula, 311. 

Freezing Point, 36. 

Fusibility, of metals, 50. 

Fusible Solids, 36. 

Fusing Point, 36. 

Gargles, 342. 

Gases, 35; diffusion of, 40; volume 
of, 37. 

Gay-Lussac's Proposition, 60. 

Glucose-syrup, 322. 

Glucosides, 308; effect of, in drugs, 309. 

Glycerin, use in pills, 322. 

Glycerites, 336; in Pharmacopoeia, 398. 

Gold, compounds of, 218, 222; descrip- 
tion of, 218; dissolves in, 137. 

Granulation, 284. 

Granules, 323. 

Gravitation, 21. 

Gums, classes of, 295; term misused, 
296. 

Guncotton, 178. 

Halides, 73; definition of, 195; formed 

by, 82. 
Halogens, 131, 194. 
Heat, 23, 35; conductors of, 50; effects 



410 



INDEX 



upon cohesion, 36; for pharmaceuti- 
cal purposes, 267; latent, 37; spe- 
cific, 60, 61; temperature, 35. 

Hydrocarbons, 202. 

Hydrogen, arsenide of, 74; boride, 74; 
carbide, 74; combines with, 48; de- 
scription of, 187; importance of, 188; 
methods of preparation of, 187, 188; 
nitride of, 74, phosphide of, 74; sili- 
cide, 74. 

Hydrogen Chlorides, 196. 

Hydrometer, 257, 258. 

Hydroxides, 74; alkaline, 130; calcium, 
84; ferrous, 119; of light metals, 131 ; 
of non-metallic elements, 131; phos- 
phoric, 120; sulphuric, 120; water- 
soluble, 223, 226. 

Hypo, 117. 

Hypochlorites, 224. 

Hypophosphites, water-soluble, 225. 

Ic, endings, 117. 

Impenetrability, 20. 

Inertia, 22. 

Infusion, definition of, 276; of cin- 
chona, 345; of digitalis, 346; of sen- 
na, 346; of wild cherry, 345; rule of, 
345. 

Infusions, in Pharmacopoeia, 398. 

Injections, 342. 

International Metric Bureau, 234; 
standards of, 242. 

Iodides, 73; insoluble, 224; soluble, 223. 

Iodine, character of, 197; polarity of, 
69; polarity, exercises, 131, 132; 
sources of, 197; specific weight of, 
197 ; tincture of, 348. 

Ions, 38. 

Irish Moss Jelly, 340. 

Iron, atomic weight of, 167; bitter 
wine of, 351; compounds of, 214, 
221; decomposes, 138; description 
of, 214; dissolves in, 143. 

Ration, 67. 

Krypton, definition of, 48. 

Lactates, water-soluble, 325. 
Lard, 325. 

Latinic Nomenclature in Pharmaco- 
poeia, 379-389. 



Law of Dulong and Petit, 61. 

Laws of Proportions, 56. 

Lead, color, 215; compounds of, 215, 
222; dissolves in and decomposes, 
138. 

Levigation, 270. 

Licorice Root, powdered, 321. 

Light, 40; effects of, 40. 

Lime, 84; sulphated, 224. 

Limestone, 84. 

Liniments, 342; in Pharmacopoeia, 
399. 

Liquids, 35; clarification of, 279; diffu- 
sion of, 40; vaporizable, 36; volatile, 
36. 

Lithium, 209; compounds of, 220; 
striking properties of, 210. 

Litmus, 142; paper, 142. 

Lotions, 341; kinds of, 342. 

Lozenges, 319. 

Maceration, 274. 

Magnesium, 185; compounds of , 212, 
220; description of, 211. 

Malaguti's Doctrine, 133, 134, 136. 

Malleability, 49. 

Managers, 13. 

Manganese, 215; compounds, 222. 

Marble, 84. 

Mariotte's Law, 37. 

Mass, 21. 

Masses, 319; in Pharmacopoeia, 399. 

Materia Pharmaceutica, 4. 

Matter, 20; chemical properties of, 30; 
compound, 27; kinds of, 25; physical 
properties of, 29; properties of, 22; 
specific properties related to energy, 
24. 

Measures and Weights, 231-247; com- 
parative tables, 243-245. 

Medicines, 3. 

Menstruum, employed in extracts, 8. 

Mercury, attacks, 139; compounds of, 
216, 217, 222; description of, 216. 

Meta-compounds, 119-122. 

Metals, alkali, 207; alkaline earth, 
210; chemical behavior of, 50, 51; 
chemical action of, 131; conductors 
of heat, 50; definition of, 26; density 
of, 49; fusibility of, 50; heavy, 213; 



IKDEX 



411 



light, 207; luster of, 49; solubility in, 
50; volatility of, 50. 

Metals, The, alkali, 207; heavy, 213; 
light, 207. 

Metaphosphates, soluble, 224, 225. 

Metathesis, 133. 

Metric System, 231-234; defects of, 235; 
tables of, 236. 

Mill, iron, 269. 

Mixtures, 8, 28; chalk, 341 ; in Pharma- 
copoeia, 399. 

Moisture, hygroscopic, 40. 

Molds, 329. 

Molecular Weight, 28, 57. 

Molecules, 27; compound, 28; elemen- 
tal, 27; molecular weights, 28, 
57. 

Morphine, 4; contains nitrogen, 178. 

Mortars, iron, 269; pill, 320; solution, 
273; trituration, 270. 

Mother -liquor, 284. 

Motion, 22; 

Mucilage, dry, 296; normal or physio- 
logical, 295; of acacia, 334; of sassa- 
fras pith, 335; of slippery elm bark, 
335; of tragacanth, 335. 

Neon, definition of, 48. 

Neutralization, 142. 

Nickel, atomic weight of, 167; com- 
pounds of, 221; decomposes, 138; 
description of, 214. 

Nitrates, soluble, 224. 

Nitride, of hydrogen, 74. 

Nitrites, soluble, 224. 

Nitrogen, combines with, 178; com- 
pounds of, 178; methods of prepara- 
tion, 177; pentoxide, 179; tetroxide, 
179. 

Nitroglycerin, 178. 

Nitrosyl, 179. 

Nomenclature, 116, 119; Latinic, in 
Pharmacopoeia, 379-389. 

Notation, chemical, 103. 

Officine, 10. 

Oils, emulsions of, 338; fixed oils, fats, 
waxes, 299; fixed oils, dissolved in, 
301; fixed ons, insoluble, 300; in 
Pharmacopoeia, 399 ; volatile, 304; 



volatile as stimulants, 306 ; volatile, 
constituents of, 304; volatile, odors 
of, 305. 

Ointments, 324; medicated, 325; 
preparation of, 325, 326. 

Oleates, in Pharmacopoeia, 399 ; water- 
soluble, 226. 

Oleoresins, 355; in Pharmacopoeia, 399. 

Operations, pharmaceutical, 267-286. 

Opium, 311; in Pharmacopoeia, 399. 

Orthophosphates, soluble, 225. 

Osmosis, 292. 

Ous Endings, 117. 

Oxalates, soluble, 225. 

Oxidation, definition of, 151, 154; ex- 
amples of , by combustion, 183-186; 
explanation of, 152-163; signifies, 
18.1. 

Oxides, 182; nitric, 179; nitrous, 179; 
phosphoric, 199; water-soluble, 223. 

Oxygen, combines with, 48; composed 
of, 180; description of, 180; impor- 
tance of, 179, 180; oxidizing agent, 
156; prepared by, 180. 

Ozone, 181. 

Pectin, 294, 295. 

Pepsin, in Pharmacopoeia, 399. 

Per, 117. 

Percentage of Strength, in Pharma- 
copoeia, 393. 

Percolation, 276-279. 

Percolator, 277. 

Periodic System, 165-173. 

Petrolatum, 326. 

Pharmaceutical Operations, 267-286. 

Pharmaceutical Stills, 281, 282. 

Pharmacist, 11. 

Pharmaco-dynamics, 10. 

Pharmacognosy, 10. 

Pharmacography, 10. 

Pharmacology, 9. 

Pharamacopoeia, eighth revision of, 
studies in, 393-406; cerates, 394; 
collodions, 394; confections, 394; 
doses, 404; emulsions, 394; extracts, 
398; formulas for preparations, 404; 
glycerites, 398; infusions, 398; lini- 
ments, 399; masses, 399; mixtures, 
399; oils, 399; oleates, 399; oleores- 



412 



INDEX 



ins, 399; opium, 399; pepsin, 399; 
percentage, strength, 393; pills, 
399; plasters, 394; powders, 399; 
preparations, 394 ; resins, 399 ; spirits, 
399; syrups, 400; tinctures, 400; trit- 
urations, 400; troches, 400; vegeta- 
ble drugs, titles of, 404; waters, 394; 
wine, 400. 

Pharmacopoeial Convention, 359. 

Pharmacopoeias, 359-377; definitions 
of, 10, 359; descriptions found in, 
367-370 ; general directions contained 
in, 375-377; .plant drugs contained 
in, 361; tests given in, 371-374; value 
of, 362, 363; working formulas of , 
375. 

Pharmacy, 4 ; laws of , 1 1 ; legitimate, 15 ; 
responsibilities of, 16, 17; scientific- 
technical, 15; training necessary in, 
14. 

Phenol Sulphonates, water-soluble, 225. 

Phosphates, soluble, 224, 225. 

Phosphide, of hydrogen, 74. 

Phosphorus, decomposed, 128 ; descrip- 
tion of, 199; ignites, 128; insoluble 
in, 199; red, 199; sources of, 200. 

Physical Bodies, 20. 

Physical Constant, 36. 

Pills, 320; coated, 323; in Pharma- 
copoeia, 399; names of, 287, 288; 
weight of, 322. 

Plasters, lead, 326, 327; in Pharma- 
copoeia, 394; mustard, 323; prepara- 
tion of, 326, 327. 

Platinum, description of, 218. 

Poisons, 3. 

Polarity, chemical, 66-69. 

Potassa, sulphated, 224. 

Potassium, atomic weight of, 166; 
bicarbonate of, 143 ; color, 208 ; com- 
pounds of, 208, 219; decomposes, 
128; occurrence, 208. 

Poultice, flaxseed, 323. 

Powders, 271; compound, 318, 319; 
dusted, 272; in Pharmacopoeia, 399. 

Precipitation, 285; chemical results 
from, 285 ; jars and flasks, 286 ; physi- 
cal results from, 285. 

Prefixes, 117; Greek used in metric 
system, 235; hypo and per, 117. 



Preparations, extemporaneous, 9; galen- 
ical, 8 ; in Pharmacopoeia, 394 ; liquid 
for external use, 341; liquid, not 
made by extraction, 333-342; official, 
10; pharmaceutical, chemical, 9; 
pharmaceutical, classification of, 
317, 318; pharmaceutical, definition 
of, 7 ; pharmaceutical, description of, 
370; pharmaceutical, Latinic titles 
of, 385-387; solid, 318-329; stock, 7. 

Products, 132; formation of a volatile, 
134. 

Proportions, combining, 53-56; laws 
of, 56. 

Pycnometer, 254. 

Pyrophosphates, soluble, 224. 

Questions, Test. See Test Questions. 
Quinine, contains, 178. 

Radicals, 133; pairing of, 136. 

Reactions, acid, 142; alkaline, 142; 
chemical, 132; chemical, definition 
of, 132; chemical, explanation of, 
133-147; mass, 145; neutral, 142; 
rule to follow, 146. 

Reagent, color, 142. 

Reducing Agent, 162. 

Reduction, definitions of, 153, 155; ex- 
planation of, 154, 155. 

Re-percolation, 279. 

Repulsion, 24. 

Resins, 307; in Pharmacopoeia, 399; 
kinds of, 307; of jalap, 356; of podo- 
phyllum, 356; of scammony, 356; 
precipitated, 356. 

Salicylates, water-soluble, 225. 

Saltpeter, 83. 

Salts, 81 ; acid, 143; acid salts neutrali- 
zed by, 142; aluminum, 212; ammo- 
nium, 178; epsom, 83,212; formed 
by alkaloids, 310; Latinic titles of 
true, 383; names of, 83; nickelous, 
138; of normal structure, 142; 
preparation of metallic, 141 ; sodium, 
145; some familiar, 83; tin, 219. 

Sand Bath, 267. 

Selenium, 199. 

Sieves, 271. 



INDEX 



413 



Silicon, crystallized, ignites in, 128; 

most abundant element, 203. 
Silver, 26; attacks, 139; compounds of, 

217,222; decomposes, 138; descrip- 
tion of, 217. 
Slippery Elm Bark, mucilage of, 335; 

powdered, 321. 
Soap, composition of, 299,300; used, 

in ointment, 325; in plasters, 327. 
Soda, baking, 83; washing, 209. 
Sodium, 127 ; carbonate, 83 ; compounds 

of, 209, 219: decomposes, 128; salt, 

83; sources of, 209. 
Solids, deliquescent, 40; fusible 36; 

soluble in, 39; volatile, 36; vapori- 

zable, 36. 
Solubility, coefficient of, 39; in alcohol, 

226; in water, 219; of metals, 

50. 
Solution, 38; chemical, 137; definition 

of, 39; formation of, 38; of soluble 

substances, 273; pharmaceutical, 8; 

water, 333, 334. 
Spatula, 270. 
Species, 318. 
Specific Gravity, Bead's, 256. See 

Weight. 
Specific Heat, 60. 
Specific Volume, 252. 
Specific Weight, 251-258. 
Spirits, 341; in Pharmacopoeia, 399. 
Starch, glycerite of, 325; glycerite, 

preparation of, 336; soluble, 293, 

294; use, 321. 
Strontium, 210; soluble compounds, 

220. 
Strychnine, 4, 6; contains, 178. 
Sublimation, 268. 
Substances, chemically homogeneous, 

29; deliquescent, 40; fixed, 36; 

gaseous, react, 136; hygroscopic, 39, 

40; physically homogeneous, 29; 

reaction of , 136, 137; titles of medic- 
inal, 364-366; volatile, introduced 

into plasters, 327. 
Substitution, 133. 
Sugar, contained in, 297; forms alcohol, 

298; kinds of, 297, 298; uses of, 297, 

298. 
Sulphates, soluble, 224. 



Sulphides, formed by , 73 ; water-soluble, 
224. 

Sulphites, soluble, 224. 

Sulphur, chemical properties of, 199; 
description of, 198; ignited, 198; 
insoluble in, 198; negative, 199; 
occurrence in nature, 198; oxidizing 
agent, 158; precipitated, 198; posi- 
tive, 199; sublimed, 198. 

Suppositories, 328; to make by hand, 
329. 

Smybol, 103. 

Synthesis, 132. 

Syrups, 335, 336; in Pharmacopoeia, 
400. 

Tablets, 319. 

Tannin, classes of. 302, 303 ; compounds 
of, 303 ; description of, 302 ; sources 
of, 302. 

Tartrates, 225. 

Tellurium, 199. 

Tenacity, 49. 

Test Questions, 18,31,42, 51,62,70, 
85, 100, 122, 147, 163, 174, 190, 203, 
228, 247, 258, 287, 312, 330, 343, 357, 
377, 389, 394, 400, 405. 

Tests, for purity, 363, 37 1 , 372 ; identity, 
371; quantitative, 373. 

Thio-sulphates, soluble, 224. 

Tin, decomposes, 138; description of, 
218; plate destroyed by, 140. 

Tinctures, 347-349; ammoniated, 350; 
ethereal, 350; in Pharmacopoeia, 
400; of fresh herbs, 349; of ferric 
chloride, 348; of iodine, 348; of 
ipecac and opium, 350; of nux 
•vomica, 350; of soap bark, 340. 

Tragacanth, 321; mucilage of, 335; use 
of powdered, 340. 

Trituration, definition of , 270; use of, 
270. 

Triturations, definition of, 319; in 
Pharmacopoeia, 400. 

Troches, 319; in Pharmacopoeia, 400. 

Units, commensurate, 253; differences 
between theoretical and actual, 
245-247; of metric system, 234, 
235; relation of units of weight 
and measure, 243-245. 



414 



INDEX 



Valence, 87; atomic, 87-90; constant, 
S9; hydrogen, 88; oxygen, 88; table 
of elements, according to, 171; vari- 
able, 91. 

Valerates, soluble, 225. 

Vaporization, 281. 

Vapor Tension, 37. 

Vinegars, 347. 

Vitriol, blue, 83; green, 83; oil of, 75; 
white, 83. 

Volume, 20; expressed by, 252; specific, 
252. 

Water, 186; aromatic, 334. 
Water Bath, 267. 
Waters, in Pharmacopoeia, 394. 
Weight, atomic, 57; definition of, 21; 
molecular, 57; specific, how found, 



253, 256; specific, 251, 258; systems 
of, and measures, 231; units of, 237. 

Weights and Measures, 231-247; com- 
parative tables, 243-245. 

Wine, in Pharmacopoeia, 400. 

Wines, medicated, 350; of antimony, 
351; of ferric citrate, 351; of iron, 
351; of ipecac, 351. 

Wood, 185. 

Work, 23. 

Xenon, definition of, 48. 

Yolk of Egg, an emulsifying agent, 340. 

Zinc, compounds of, 213, 220, 221; 
decomposes, 138; description of, 213; 
dissolves in, 143. 



